Frederic Francis Burghard

OPERATIONS UPON THE EAR
BY
HUNTER F. TOD, M.A., M.D. (Cantab.), F.R.C.S. (Eng.)
Aural Surgeon to the London Hospital

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CHAPTER I
EXAMINATION OF THE EAR: GENERAL CONSIDERATIONS
WITH REGARD TO OPERATIONS

In order to perform successfully the various operations upon the ear, it is essential that the surgeon should be familiar with the technique of its examination, which, for the sake of convenience, will first be briefly described.

EXAMINATION OF THE EAR

Clar’s Lamp Fig. 171. Clar’s Lamp.

For this purpose it is necessary to make use of certain instruments in order to obtain a clear view of the deeper parts of the auditory canal and tympanic membrane. Most important amongst these are the following:—

Mirror. A head-mirror, such as the ordinary laryngological mirror with a focus of eight inches, is to be preferred to the hand-mirror, as it leaves both hands free for manipulation.

Sources of illumination. Although the light reflected from the sky on a bright cloudless day is excellent, it can seldom be made use of, and so for practical purposes the source of light is usually artificial. It is wiser always to use the same kind of light—for instance, electric—as in this way a more accurate comparison can be made of the various pathological conditions seen on examination. In the consulting room, the lamp recommended by Dr. Greville Macdonald, furnished either with a thirty-two candle-power frosted burner or with a Nernst light, is most suitable. As a portable lamp, it is useful to have an electric bull’s-eye lamp, run off from a dry-celled battery: it can be held in the position of the ordinary lamp, the light being reflected into the ear by means of the head mirror. The ordinary surgical head-lamp, although not well adapted for inspection of the deeper parts of the auditory canal, is eminently suited for obtaining good illumination during the performance of the mastoid operations; or in its stead a head-mirror with lamp attached may be used, as recommended by Clar (Fig. 171).

Aural specula. Of the various aural specula employed, Gruber’s is very good (Fig. 172). A special speculum in which a portion has been removed from the narrow end is sometimes useful in order to facilitate operative procedures within the external meatus.

Forceps. The best are angular spring forceps with bulbous points (Fig. 173).

Gruber’s Aural Speculum Fig. 172. Gruber’s Aural Speculum.

Angular Spring Forceps Fig. 173. Angular Spring Forceps.

Position of the patient. The patient should sit upright in a chair with the side to be examined turned towards the surgeon. To prevent movement, the head should be supported by an assistant or by a head-rest fixed to the back of the chair. The lamp is placed a little behind and to the left of the patient’s head, on a level with the head of the examiner.

Technique of examination. To convert the external meatus into a straight canal, the auricle has to be pulled backwards and downwards in an infant, backwards in a child, and backwards and upwards in an adult. The speculum should be warmed and inserted gently into the meatus by the thumb and index-finger of the left hand, whilst the pinna is held between and pulled back by the second and third fingers (Fig. 174). This leaves the right hand free for manipulation. The largest possible speculum should be used, in order to give the maximum amount of room and illumination. It should only be introduced into the meatus as far as the adaptable cartilaginous portion permits—about half an inch in the adult—and not forced into the bony portion. The utmost gentleness is essential in order to obtain the confidence of the patient; this is absolutely necessary for the performance of the various small operations upon the auditory canal and tympanic cavity under local anÆsthesia.

Examination of the Ear Fig. 174. Examination of the Ear.

Aural Forceps holding Cotton-wool Fig. 175. Aural Forceps holding Cotton-wool.

Method of cleansing the ear. Except when the auditory canal is completely blocked by inspissated pus, cerumen, or epithelial dÉbris, it is sufficient to mop out the ear with small pledgets of cotton-wool. To prevent injury to the walls of the meatus and to the tympanic membrane, the pledget is held between the blades of the forceps in such a fashion that it partially projects beyond its points (Fig. 175). The forceps is passed through the lumen of the speculum along the auditory canal and then quickly withdrawn. This is repeated with fresh pledgets until the meatus is cleansed. If there is much purulent discharge, only a brief moment may be given (after the withdrawal of the forceps) in which to inspect the deeper parts. Such a view, however, should always be obtained in order to form an accurate diagnosis. If this method fails to cleanse the ear, syringing becomes necessary.

Technique of syringing. The patient should be sitting down, as syringing may cause giddiness. The fluid should be aseptic, and at a temperature of 100° F. The patient’s head is inclined to the affected side, and the auricle is pulled upwards or backwards. The syringe is inserted a short distance within the meatus, and applied to the upper posterior wall so that the stream of lotion flows along the roof of the canal to the drum, and returns along the floor, thus washing out the contents. The best syringe is one with a metal plunger, as it can be easily sterilized. After syringing, the auditory canal should be dried and again inspected. If the inspissated pus or epithelial dÉbris cannot be removed by simple syringing, an ear-bath of warm hydrogen peroxide (10 vols. %) should be given, and the ear again syringed after ten minutes.

Milligan’s Intratympanic Syringe Fig. 176. Milligan’s Intratympanic Syringe.

Syringing out of the attic. In certain cases of chronic attic suppuration, it is advisable to syringe out the attic. For this a special syringe is necessary. It consists of a fine canula whose point is turned up almost at right angles to its shaft (known as Hartmann’s canula), to which is fitted a piece of india-rubber tubing and a ball syringe. Milligan’s modification of this instrument is now generally used, as it permits of the canula being held in the hand, and instead of having a ball syringe, is connected by rubber tubing to a small irrigator (Fig. 176).

The patient sits upright in a chair in the ordinary position for examination of the ear; a speculum is inserted into the meatus, and held in position with the left hand; the canula, together with the ball syringe (if Hartmann’s is used), is held in the right hand. Under good illumination the canula is passed inwards along the auditory canal, and its point inserted through the perforation. By gently pressing on the syringe, the fluid is forced into the attic, which is thus washed out.

With Milligan’s instrument, the irrigator is fixed about two feet above the level of the ear. While the canula is being inserted, the escape of lotion is prevented by compressing the tube against the shaft of the instrument by means of the thumb. After the canula has been inserted into the opening, relaxation of this pressure permits of flow of the lotion. Milligan’s method is better than Hartmann’s, as the surgeon has more control over the instrument. Pain due to the introduction of the canula may be greatly minimized by previously inserting within the margins of the perforation either a pledget of cotton-wool soaked in a saturated solution of cocaine, or a crystal of cocaine.

After the cavity has been thoroughly washed out, the auditory canal is carefully dried as a final step, gentle inflation by Politzer’s method may be performed in order to expel any fluid still remaining within the attic.

GENERAL CONSIDERATIONS WITH REGARD TO OPERATIONS

In this connexion two points must be borne in mind: (1) The surgeon must have a good view of the part operated upon. For this reason when operating upon the auditory canal, the tympanic membrane, and tympanic cavity, he will usually require to work by reflected light.

(2) There must be no movement of the patient’s head during the operation. If the operation is performed under a local anÆsthetic, it is therefore very important that the patient’s head should be kept fixed by means of an assistant.

Preliminary surgical toilet. If there be no existing suppuration, the ear should be cleansed, some twelve hours before the operation, by first giving an ear-bath of hydrogen peroxide lotion. This is done by making the patient incline the head to the opposite side so that the affected ear is uppermost. The warm solution is then poured into the meatus. After ten minutes the ear is syringed out with a 1 in 5,000 aqueous solution of biniodide of mercury, and a strip of sterilized gauze is then inserted into the auditory canal. The auricle and surrounding parts should also be surgically cleansed, and afterwards protected by a simple aseptic compress. If, as in furunculosis of the external meatus, syringing or cleansing of the ear is very painful, drops of a 10% solution of carbolic acid in glycerine may be instilled frequently into the meatus instead. If there is an existing otorrhoea, it is obviously impossible to render the field of operation absolutely aseptic. The ear, however, should be cleansed, but the auditory canal should not be plugged with gauze. The existence of a purulent discharge is no excuse for lack of cleanliness. Failure of such precautions may lead to disaster; for example, to perichondritis of the auricle as a sequel of the mastoid operation.

Before the actual operation takes place, if necessary after the anÆsthetic has been given, the ear and surrounding parts should again be carefully cleansed, and the auditory canal syringed out with biniodide of mercury solution.

In intrameatal operations the head should be wrapped in a sterilized towel, and a square of sterilized lint, having an aperture in the centre so as to expose only the auricle and meatus, should be placed over the side of the head and face. In operations on the mastoid process, and in those involving a post-auricular incision, the head should also be shaved for at least two or three inches beyond the region of the ear.

AnÆsthesia. Both local and general anÆsthesia are used. Unless contra-indicated for some special reason, and unless the operation is a very trivial one, it is wiser to give a general anÆsthetic. Of these, chloroform is the most suitable in adults and infants, and the A. C. E. mixture in children. Ether, although it may be safer, is frequently a source of annoyance to the operator, as it tends to increase the hÆmorrhage.

In order to produce local anÆsthesia two methods may be employed: (1) The instillation of fluids into the meatus; (2) subcutaneous injection of fluids beneath the lining membrane of the meatus and into the surrounding parts of the auricle.

The solution usually employed is a sterilized aqueous solution of cocaine hydrochloride in varying strengths up to 20%, to which may be added equal parts of 1 in 1,000 adrenalin chloride solution; the latter not only increases its analgesic properties, but also acts as a powerful hÆmostatic.

Instillation. As the auditory canal and the tympanic membrane are lined with epithelium which is very resistant to the absorption of fluids, complete anÆsthesia is almost impossible to obtain. This method, therefore, is practically limited to such trivial operations as the curetting away or snaring off of granulations or polypi from the external or middle ear. To render anÆsthesia more complete, the affected part may be finally rubbed over with a crystal of solid cocaine hydrochloride just before the operation—is begun. On the other hand, if the raw surface is large—for example, the wound left after a recently performed complete mastoid operation—the cocaine employed should not be stronger than a 5% solution in order to minimize the risk of poisoning. Gray of Glasgow has suggested, as a more penetrating anodyne solution, a mixture consisting of a 10% solution of cocaine hydrochloride in equal parts of aniline oil and absolute alcohol, a solution which he especially advocates in order to produce anÆsthesia of the tympanic membrane before doing paracentesis.

Subcutaneous injection. This is a modification of Schleich’s method, and was first introduced by Neumann of Vienna. It consists in injecting a very weak solution of cocaine and adrenalin chloride subcutaneously beneath the periosteum lining the auditory canal. By this method even the complete mastoid operation has been performed, and in certain clinics it is used continually in the minor operations of paracentesis of the tympanic membrane, division of intratympanic adhesions, extraction of polypi, and ossiculectomy. A solution of beta-eucaine or novocaine may be used in preference to cocaine, as being less dangerous. According to Neumann, three solutions are necessary: (a) a 1 in 2,000 solution of adrenalin chloride containing a 1% solution of beta-eucaine; (b) a 1 in 3,000 solution of adrenalin chloride containing a 1% solution of cocaine; (c) a 20% solution of cocaine.

Neumann’s Syringe for Subcutaneous Injection Fig. 177. Neumann’s Syringe for Subcutaneous Injection.

The syringe for injecting the solution has a capacity of 1 cubic centimetre, and for convenience its needle is fixed at an obtuse angle to the body of the syringe (Fig. 177). The technique of the injection depends on whether the operation is to be limited to the auditory canal and tympanic cavity, or is to involve the mastoid process.

If the complete mastoid operation is going to be performed, the needle of the syringe, now filled with the eucaine solution, is thrust through the skin about the middle point of the mastoid process, and a few drops of the solution are injected. The needle is then forced upwards towards the temporal ridge, at the same time being thrust in deeply until it touches the bone, so that a syringeful of the solution is injected beneath the periosteum. The needle is then withdrawn and reinserted at the same point, but in a backward direction, the solution being injected along the posterior portion of the mastoid process; in a similar manner the solution is injected downwards towards the tip of the mastoid. The ear being now pulled well forward, the needle is made to pierce the fold between the auricle and the mastoid process, just above the posterior ligament, and is pushed inwards between the anterior border of the mastoid process and the cartilage of the meatus, and a further syringeful of the solution is injected. A large speculum is now inserted into the ear, so that by pressing it against the wall of the meatus the skin, at the termination of the cartilaginous portion, is made to project in folds. The needle of the syringe, filled with cocaine solution, is pushed into this fold, and a few drops of the solution injected. By degrees the needle is still further pushed inwards, keeping it in close contact with the bony wall so that the fluid is injected beneath the periosteum. If the injection has been successful, a white bulging of the superior wall of the auditory canal will be noticed. To render anÆsthesia complete, further injections may be made into the inferior and anterior walls of the auditory canal. Finally, a pledget of cotton-wool soaked in a 20% solution of cocaine is pushed into the tympanic cavity.

In the case of simple opening of the mastoid, subcutaneous injections into the auditory canal are not necessary. On the other hand, if the operation is limited to the auditory canal and tympanic cavity, the injections into the mastoid process are not required, but a primary injection of a small quantity of eucaine solution into the auriculo-mastoid fold considerably diminishes the pain produced during the act of injection into the auditory canal. Fifteen minutes should be allowed to elapse before the operation is begun. The anÆsthesia lasts about half an hour.

Difficulties. It is by no means easy to inject fluid beneath the periosteum of the auditory canal, owing to its close adherence to the bone. The needle by mistake may repierce the skin at a point farther in, so that the fluid, instead of being injected beneath the periosteum, is injected into the auditory canal itself. In these cases anÆsthesia will not be obtained, and the operator may possibly blame the principle of subcutaneous injection, rather than his own faulty technique.

In favour of subcutaneous injection it is urged that most of the minor operations within the tympanic cavity, including ossiculectomy, may be performed with the patient sitting up in the chair in the consulting room, and further, that the patient can afterwards go home; that the operation is rendered more easy owing to there being practically no bleeding; and that in the case of the more severe operations, such as opening of the mastoid antrum, the surgeon, in a case of emergency, may make use of this method if he cannot possibly obtain the services of an anÆsthetist.

Against subcutaneous injection is the pain of the injection, which may be so great that the patient will not submit to it, and in consequence the proposed operation may have to be postponed.

In the case of the mastoid operation, it is difficult to believe that local anÆsthesia, however efficient, will be looked upon with favour either by the surgeon or by the patient, except when a general anÆsthetic is absolutely contra-indicated. The discomfort produced by retraction of the parts, the jarring caused by chiselling, and the consciousness of what is taking place, are far more unpleasant and more of a shock to the patient, than a general anÆsthetic carefully given. Further, it is not always possible to foretell the extent of the operation, and if repeated injections become necessary, there is danger of eucaine or cocaine poisoning being produced.

Position of the patient and the surgeon

1. In the minor operations the patient may be operated on whilst in the sitting posture, whether a local anÆsthetic or a general one of gas and oxygen is employed. The relative positions of the patient and the surgeon are then the same as for the ordinary routine examination of the ear. Special care, however, should be taken that the patient’s head is supported by the anÆsthetist or assistant in order to prevent involuntary movements.

2. If the patient is operated on in the recumbent position, the head may rest comfortably on an ordinary pillow, but if chiselling is going to take place, the best support is a loosely filled sand-bag. The head should be turned towards the opposite side so that the affected ear is uppermost, and the surgeon stands at the side to be operated on. The lamp, the source of reflected light, should be held about six inches above the patient’s shoulder on the opposite side.

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CHAPTER II
OPERATIONS UPON THE EXTERNAL AUDITORY CANAL

OPERATIONS FOR FURUNCULOSIS

The operative treatment consists in incising the furuncles and, if necessary, curetting out their contents.

Indications. (1) If, in spite of palliative treatment for two days, the pain be so intense as to prevent sleep, and be accompanied by pyrexia.

(2) If there be accompanying oedema of the auricle and surrounding parts.

(3) If the furuncles occur during the course of a middle-ear suppuration, and occlusion of the external meatus prevents free drainage of the purulent secretion.

When possible, it is always preferable to operate under a general anÆsthetic, such as gas and oxygen. If, however, the patient objects to a general anÆsthetic, it should be explained that, in spite of the application of anodynes, the operation, although of momentary duration, will be excessively painful.

Operation. After the ear has been thoroughly cleansed, a large aural speculum is inserted within the meatus and the auditory canal dried with pledgets of cotton-wool.

The instrument usually used for this operation is a small and narrow sharp-pointed knife known as Hartmann’s furunculotome (Fig. 178, C). Equally suitable, however, is a fine bistoury; or, if necessary, a small tenotome or the ordinary paracentesis knife.

Burkhardt-Merian’s Aural Instrument Fig. 178. Burkhardt-Merian’s Aural Instrument.

A. Curette. B. Myringotome. C. Furunculotome.
D. Hook for removal of foreign body.

The surgeon holds the speculum in position within the meatus with the left hand, and with the right inserts the knife through the lumen of the speculum along the meatus until its point passes the innermost limit of the furuncle. It is then quickly withdrawn, at the same time incising the furuncle freely down to its base. Another method is to transfix the furuncle by passing the knife through its base and making it cut outwards through the skin. In a similar manner any other furuncles that may be present are incised or transfixed.

If the inflammatory process, instead of being localized as a furuncle, extends to the subcutaneous tissues, and especially if it is accompanied by much pain, pyrexia, and occlusion of the external meatus, linear scarification may become necessary.

After incision, the contents of the furuncle are rapidly scooped out with the curette (Fig. 178, A). Slight hÆmorrhage may occur, but can be arrested at once by plugging the meatus for a minute with a strip of sterilized gauze. The auditory canal is finally syringed out with a warm aqueous 1 in 5,000 solution of biniodide of mercury and firmly plugged with gauze soaked in a 10% solution of carbolic acid in glycerine; a hot fomentation being afterwards applied to the side of the head.

If the operation has been performed under a local anÆsthetic (and this should only be done if a solitary furuncle is present), the pain is usually too great to permit of firm packing of the auditory canal. This after-packing, however, should be carried out, if possible, for the following reasons: firstly, it presses out the contents of the furuncle; secondly, it prevents auto-infection from one hair follicle to another; and thirdly, it tends to dilate the auditory canal.

After-treatment. If the furuncles have occurred during the course of a middle-ear suppuration, the gauze plugging must be removed within a few hours after the operation. The ear is then syringed out once or twice daily with a warm solution of lysol or carbolic acid, a small wick of gauze soaked in a 10% solution of carbolic acid in glycerine being afterwards inserted along the meatus.

If there be no accompanying middle-ear suppuration, the packing should not be removed for at least twenty-four hours. The pain produced by the first dressing may be severe, but can be usually avoided by first soaking the gauze with 5% solution of cocaine for a few minutes before removal and then gently withdrawing it whilst the ear is being syringed with a warm aseptic lotion. For the next two or three days it is sufficient to insert a drain of gauze soaked in a 1 in 3,000 alcoholic solution of perchloride of mercury.

Results. Although cure may be expected, it is not uncommon for further furuncles to occur in crops at repeated intervals. This is due to auto-infection of the hair follicles, which to a large extent may be prevented by painting the surface of the auditory canal daily, for at least two or three weeks, with an oil containing a drachm of nitrate of mercury to the ounce.

In the case of diffuse inflammation, although relapses are uncommon, superficial necrosis of a portion of the bony meatus may afterwards occur as a result of involvement of its periosteal lining. If this takes place, stenosis of the auditory canal may afterwards occur from subsequent cicatrization.

Dangers. With ordinary precautions no accident should occur, but the following may be mentioned: (1) if the furuncles are deeply placed, the tympanic membrane may be incised inadvertently, and a middle-ear suppuration may result; (2) a too violent incision may cut through the meatal cartilage posteriorly, and, as a result of septic infection, may give rise to perichondritis of the auricle. This, fortunately, is rare.

REMOVAL OF EXOSTOSES FROM THE EXTERNAL MEATUS

Indications. The indications vary, depending on whether there is a coexisting middle-ear suppuration or not.

If there be no middle-ear suppuration. Operation is not urgent, but is justifiable under the following conditions:—

(i) When one ear only is affected. (a) If there be complete deafness due to obstruction of the auditory canal. The question of operation, however, should be decided by the patient, because it may be postponed indefinitely so long as no symptoms occur.

(b) If there be recurring attacks of discomfort or of pain in the ear as a result of eczema, of otitis externa, or of actual pressure of the growth itself. The patient may desire operation to obtain permanent relief.

(c) If there be deafness of the opposite side from other causes, and the presence of the exostoses is causing deafness of the functionally good ear.

(ii) When both ears are affected. In addition to the indications already given, operation is advisable on the worse side if there be almost complete obstruction on both sides, accompanied by recurrent attacks of deafness, owing to the narrowed passage of the auditory canal becoming repeatedly blocked from accumulation of cerumen or epithelial dÉbris.

Operation is contra-indicated if previous examination indicates that the deafness is due to a chronic middle-ear catarrh or internal-ear disease, as in these cases restoration of hearing, which is the primary object of the operation, will be impossible.

If middle-ear suppuration be present operation is generally advisable.

(i) In acute middle-ear suppuration operation is urgent if there are signs of retention of pus, provided it is impossible to dilate the lumen of the auditory canal. Before resorting to operation an attempt should always first be made to obtain free drainage, as the obstruction may be due merely to inflammatory swelling of the tissues lining the auditory canal. With cessation of the acute inflammation, this swelling may subside and the lumen of the auditory canal again become patent; and if recovery with healing of the tympanic membrane takes place the hearing may again become normal, rendering the operation no longer necessary.

(ii) In chronic middle-ear suppuration operation is always indicated if there are symptoms of retention of pus. It is also advisable as a prophylactic measure, although not urgent, even although no acute symptoms are present.

Operation. When there is no middle-ear suppuration.

The operation may be performed either (a) through the external meatus or (b) by reflecting the auricle forward by a post-auricular incision.

Through the external meatus. This method is only indicated if the exostosis is situated at the entrance of the meatus and is pedunculated.

A general anÆsthetic is given, the patient being in the recumbent position. The surgeon works by reflected light. After the ear has been thoroughly cleansed a large-sized aural speculum is inserted into the meatus and the outlines of the exostosis are defined with a probe. A small gouge or chisel is used. It is inserted into the meatus in such a fashion that its point presses between the pedicle of the exostosis and the wall of the bony meatus. With successive sharp taps of the mallet, the gouge is made to cut through the pedicle, care being taken that the instrument is not driven in too deeply, on to the tympanic membrane.

The growth, which can now be felt to be movable within the meatus, can usually be removed by grasping it between the blades of forceps, or can be expelled by syringing the ear. After its removal the auditory canal should be plugged for a few minutes with a solution of cocaine and adrenalin chloride. This checks all hÆmorrhage, and at the same time enables the surgeon to get a good view of the deeper parts to see if further growths are situated more deeply within the meatus. Such growths, provided they are pedunculated and do not abut on the tympanic membrane, can sometimes also be removed by the same method; much depends on their shape and situation. If sessile or too deeply placed, the operation may have to be completed by reflecting forward the auricle. Before terminating the operation a clear view of the tympanic membrane should always be obtained.

The meatus is finally syringed out with a 1 in 5,000 aqueous solution of biniodide of mercury and dried, a strip of sterilized gauze being inserted into the auditory canal. A simple dressing is then applied to the side of the head.

Other methods of operation through the external meatus.

(a) Perforation of the exostosis, or enlargement of the small passage existing between multiple exostoses, by means of the burr.

Although successful results have been recorded, this method is not advised, as cicatricial tissue almost invariably causes closure of the opening made. To keep the opening patent it is necessary to insert a small lead or silver canula, frequently a source of great discomfort.

(b) If the exostosis has a very fine pedicle, it may be possible to nip through its base with a pair of forceps, but it is not so sure a method as the employment of a gouge and mallet.

(c) Such methods as attempts to destroy the growth by means of the galvano-cautery or by the pressure of laminaria tents should be avoided; they are useless and unsurgical.

By reflecting the auricle forward. This is indicated if the exostoses are multiple, have a broad base, and are deeply situated.

The position of the patient, and the anÆsthetic, are the same as in the previous operation. Reflected light may not be necessary.

The ear and the surrounding parts are carefully cleansed and the head is shaved for a short distance over and beyond the mastoid process. A curved incision is made close behind the auricle (Fig. 226), beginning at the upper level of its attachment and extending downwards along the retro-auricular fold. The incision goes down to the bone. The auricle is reflected forward and the soft tissues are separated from the bone until Henle’s spine and the posterior upper margin of the auditory canal are brought into view. Any bleeding, chiefly from branches of the posterior auricular artery, is at once arrested by pressure forceps, ligatures being afterwards applied. The assistant’s duty is to hold the auricle well forward and at the same time to keep the wound dry by swabbing.

The fibrous portion of the canal is carefully separated from the bony portion with the periosteal elevator, the growth, if possible, being exposed without tearing through the thin layer of skin which covers it.

The method of procedure now depends on the character and number of the exostoses present.

(a) If situated superficially, they are removed by chiselling through their base with a gouge. They should be thoroughly removed, if necessary cutting through the normal bone well behind their base.

(b) If deeply placed, they are more easily removed by first chiselling away a part of the upper posterior wall of the external meatus. This is done in the same manner as in the early stage of the complete mastoid operation (see p. 397). If possible the antrum should not be exposed, and care should be taken not to cut too deeply for fear of injuring the tympanic membrane.

(c) If the exostoses spring from the anterior wall, it is necessary to make a T-shaped incision through the posterior membranous portion of the auditory canal in order to bring them into view clearly. This is done with a tenotomy knife, the flaps being held apart by means of forceps. The growths can now be removed by means of the gouge and mallet.

(d) If the obstruction is due to multiple small exostoses forming an annular stricture within the bony canal, it is better to separate the membranous portion completely from the bony meatus. In doing so the skin over the exostoses tears through, so that the membranous portion can be reflected outwards as a finger-like process. To give greater room for the operation, the auricle and fibrous portion are pulled well forward by means of a loop of gauze passed through the lumen of the cartilaginous meatus.

If necessary, reflected light should now be used. To reach the exostoses it may be necessary, as in the previous case, to remove part of the posterior bony wall. With the gouge and mallet the exostoses are carefully chiselled away. They frequently abut on the tympanic membrane, so that their removal without injuring it may be well-nigh impossible. It is of the utmost importance that the field of operation should be kept dry, if necessary by repeatedly mopping out the canal with pledgets of cotton-wool soaked in adrenalin solution. The chief difficulty is to determine the situation of the tympanic membrane. A fine probe is used to discover any existing chink between the growths; this will be a guide to show the direction in which to work. As soon as a small passage has been made, sufficient to allow of a view of the deeper-lying parts, the ear should be syringed out and dried, and a thorough inspection made. The tympanic membrane can usually be seen as a greyish-blue membrane; at other times it can be recognized by touching it with a probe. After making certain of the position of the membrane, the rest of the operation is easy. A small seeker (Fig. 219), such as is used in the mastoid operation, is passed through the opening already made, and with it the deeper limits of the exostoses can be felt. The opening is gradually enlarged by removing the growths piecemeal with the chisel or gouge.

Although the burr is contra-indicated when operating through the external meatus, it is frequently of great service in these cases in rendering the walls of the canal smooth. The disadvantages of using a burr are, that it is less easy to control (unless the surgeon has had considerable experience in using it), and that it destroys all the epithelial lining of the auditory canal with which it comes in contact. It should, therefore, only be used in those cases in which there is a complete ring of exostoses, but should be avoided if the exostoses are limited and if it is still possible to leave untouched a portion of the epithelial lining of the auditory canal.

When the surgeon considers he has successfully removed the obstruction, he should verify this fact by syringing out and drying the ear, and again obtaining a clear view of the tympanic membrane.

The fibrous portion is now replaced by inserting a finger into the cartilaginous meatus and pressing it back into the bony canal, the auricle being meanwhile pulled back into its normal position. The edges of the posterior wound are sutured together and the auditory canal is gently packed with gauze which should be inserted right down to the tympanic membrane. It is not necessary to make special meatal skin flaps, as careful packing of the auditory canal should be sufficient to keep the parts in apposition.

When middle-ear suppuration is present. In acute middle-ear suppuration the chief difficulty is to decide what operation to perform. As operation is only indicated if there is retention of pus, it is wiser to open the mastoid antrum; the exostosis, if superficial and pedunculated, can also be removed at the same time. If, however, the obstruction is due to multiple and deeply placed exostoses, this part of the operation should be deferred to a later date, that is, after the acute symptoms have subsided.

In chronic middle-ear suppuration the only operation to be recommended is the complete mastoid operation (see p. 392).

After-treatment. The after-treatment is practically the same whatever operation has been performed. The first dressing need not be done until the third day. The gauze plugging is then withdrawn and the auditory canal is syringed out and dried. If only a single exostosis has been removed the wound surface is small, and it is usually sufficient to puff in some boracic powder and again insert a piece of gauze. This may be repeated every second day, healing usually taking place within two or three weeks. In the case of deeply situated multiple exostoses, especially if removed from the anterior wall, considerable swelling of the soft parts lining the auditory canal may occur as a result of the manipulations. In such cases, after syringing out any existing blood-clots, some cocaine and adrenalin solution should be instilled into the meatus. An aural speculum is then gradually worked into the auditory canal, which is gently mopped out with small pledgets of cotton-wool, and the deeper parts are carefully inspected. Sometimes the torn ends of the fibrous portion, instead of covering the bony walls, are found to project into the auditory canal and to cause considerable narrowing of its lumen. By careful manipulations with the probe or by stroking the edges with tiny pledgets of cotton-wool, these rough surfaces may be smoothed down. It is very important, in the early days of the after-treatment, to prevent any narrowing at the site of the operation. This is one of the chief causes of subsequent failure. The gauze should always be reinserted right down to the tympanic membrane, and if there is not much secretion it should be packed firmly against the posterior and outer portion of the canal in order to prevent subsequent stenosis from the tendency of the cartilage to prolapse forward owing to the soft parts having been separated from the bony canal at the time of the operation.

The wound behind the ear heals very quickly and the stitches can generally be removed on the third or fourth day. Subsequent treatment consists in preventing the formation of granulations over the wound area. This is best accomplished by keeping the auditory canal aseptic and dry. If granulations occur they should be touched from time to time with a saturated solution of trichloracetic acid. If healing has not taken place within two weeks, it will frequently be advantageous to discontinue the gauze packing and, in its stead, to instil drops of pure rectified spirit.

If a middle-ear catarrh with secretion of fluid occurs, owing to the tympanic membrane having been injured, it may be impossible to continue the gauze packing. In these cases only a fine drain of gauze should be inserted into the meatus, the dressing being changed as frequently as may be necessary.

Provided asepsis is maintained, the middle-ear inflammation usually subsides rapidly with healing of the membrane. After healing has taken place, inflation of the middle ear is recommended twice a week, for two or three weeks, in order to aid recovery and to prevent adhesions forming within the tympanic cavity.

Dangers. 1. If the exostoses be deeply situated, the tympanic membrane may be injured.

2. If much of the anterior wall of the auditory canal be removed, the temporo-maxillary joint may be opened.

3. It is possible that the tympanic membrane may not be recognized, and, by working too deeply, the labyrinth or the facial nerve may be injured.

Prognosis. Provided no accident has occurred during the operation, a successful result should be obtained. Stenosis, however, may occur from cicatricial contraction if the operation has been incompletely performed.

REMOVAL OF FOREIGN BODIES

Before considering the question of removal of foreign bodies, the following points cannot be emphasized too forcibly:—(1) No attempt should be made to remove a foreign body until it is certain that one really exists. (2) Provided there is no middle-ear suppuration, a foreign body left in the ear will very rarely cause any immediate harm. (3) The most serious complications are due almost invariably to ill-advised haphazard attempts to remove the foreign body; as a rule from working blindly in the dark without making use of reflected light.

If a foreign body be suspected, the surgeon should first carefully examine the auditory canal in order to determine its character and position and the condition of its walls. On this will depend the treatment to be employed.

If the object be a living insect it should be killed at once by the instillation of warm oil, rectified spirit, or chloroform. This will cause immediate relief of the intense pain and tinnitus which may have been set up by its movements against the sensitive tympanic membrane.

The methods employed for the removal of a foreign body are syringing, extraction by instruments through the external meatus, and removal by operation by making a post-auricular incision and reflecting forward the auricle.

By syringing. In the vast majority of cases syringing is successful, and therefore should always be tried except under the following conditions:—(a) If the foreign body be of such a nature that it may be driven inwards; for example, a percussion cap for a toy pistol, lying with its concavity outwards.

(b) If there be much inflammation and swelling of the walls of the external meatus, unfortunately frequently due to previous unsuccessful attempts at extraction by instruments. In such cases forcible syringing may cause considerable pain, and in addition immediate removal of the foreign body may be impossible owing to the temporary occlusion of the meatus.

Unless urgent symptoms of retention of pus behind the foreign body are present, it is wiser to wait for a few days until the inflammation has subsided, in order that the canal may become more patent and permit of a more favourable opportunity for removal of the foreign body. The auditory canal, in the meanwhile, may be mopped out two or three times a day with pledgets of cotton-wool, and a 1 in 5,000 alcoholic solution of biniodide of mercury afterwards instilled into the ear.

The method of syringing has already been described (see p. 308). The syringe should be a large one with its tip protected by some india-rubber tubing. The point is inserted within the meatus up against the foreign body and the stream of lotion is directed towards any chink which may exist between it and the auditory canal. It may be necessary to use many syringefuls with considerable force before the foreign body can be expelled, but the syringing should be stopped if pain or giddiness are caused.

If the foreign body cannot be removed at the first attempt, drops of rectified spirit may be instilled into the ear several times a day, provided there are no urgent symptoms. This will tend to diminish any swelling of the soft tissues of the external meatus and of the foreign body if it is a vegetable substance. The ear should again be syringed after two or three days. In many cases this will now be successful; if not, the foreign body may be moved gently with a probe (using a speculum and reflected light), great care being taken not to push it further into the auditory canal, and another attempt may be made to remove it by prolonged syringing. If this fails it may be left in situ for a still longer period, provided there are still no symptoms requiring its immediate removal. In some cases, instead of the instillation of alcohol, a 5% solution of carbolic acid in glycerine or olive oil proves more effectual.

In the case of a hard substance, repeated attempts may be made to dislodge it before resorting to further measures; but in the case of a soft vegetable substance like a pea, it must not be forgotten that moisture tends to make it swell and perhaps will necessitate almost immediate extraction by instruments.

A, Points of crocodile forceps, full size.
B and C, Aural punch-forceps.
D, Aural scissors.

Extraction by instruments.

Indications. (i) If inspection shows that the foreign body can at once be removed by a suitable instrument: for example, a percussion cap the edge of which may be grasped by a pair of forceps (Figs. 179 and 193); or a small boot button whose shank, if it faces outwards, may be caught by a small hook.

(ii) If repeated attempts have failed to remove the foreign body by syringing.

(iii) If previous attempts by others have failed, and the foreign body has been pushed in beyond the isthmus, and cannot be removed after prolonged syringing.

(iv) If syringing produces violent giddiness, showing the probable presence of a perforation of the tympanic membrane.

(v) If there be symptoms of acute inflammation of the middle ear or of pus being pent up behind the foreign body.

Operation. An anÆsthetic may not be necessary in adults if the foreign body is not too deeply placed within the ear, if its removal appears to be a simple matter, and if the patient is of a placid temperament. Otherwise, unless contra-indicated for some special reason, a general anÆsthetic should always be given in children, and it is also preferable in adults for the following reasons:—(1) Inability to remove the foreign body after repeated attempts by syringing usually means that its extraction by instruments will be a somewhat difficult matter. (2) The risk of injury to the meatal walls or tympanic membrane from involuntary movements of the patient during the operation is far greater than the risk of the anÆsthetic. (3) If the foreign body cannot be removed through the meatus by means of instruments, the post-meatal operation is indicated. This, if necessary, can be done at once if the patient is under a general anÆsthetic.

If no anÆsthetic is given the patient may sit up in a chair; otherwise, the recumbent position is advised.

It is usually necessary to use an aural speculum, but if the foreign body be situated near the entrance of the meatus a sufficient view may be obtained by pulling the tragus forward and the auricle backward. Good illumination is essential.

(i) If the body be a soft substance, such as a pea, the core of an onion, or a fragment of wood, it is best removed by fixing into it some form of sharp hook (Fig. 178, D). These hooks vary in shape. They may be curved, or shaped like a crochet-hook, or have the sharp point placed at right angles to the shaft of the instrument.

In the case of a round substance like a pea, especially if it is tightly impacted within the meatus, its removal is sometimes facilitated by first slicing it into pieces by means of a small bistoury.

As a rule, the foreign body is impacted at the junction of the cartilaginous and bony portion of the auditory canal; sometimes, however, it is more deeply situated within the osseous meatus, usually the result of previous attempts to extract it.

In the former case, the instrument is passed along the upper posterior wall of the canal between it and the foreign body, the point of the hook being kept upwards or downwards so as not to project into the auditory canal. The instrument is first passed well beyond the foreign body, and then the shaft is twisted round so that the hook projects into the auditory canal. With a quick movement it is drawn outwards a short distance so that the point of the hook pierces the impacted substance. Gentle traction is now used and in the majority of cases the foreign body can be extracted.

If this fails, a slightly curved fenestrated scoop (Fig. 180) or curette should be passed, if possible, between the foreign body and the anterior wall of the auditory canal. The hook already fixed into the foreign body prevents it from being driven further within the meatus, whilst the scoop, if it can be got beyond the foreign body, can usually lever it out.

If the foreign body has been pushed in beyond the isthmus and lies deeply within the osseous canal, it is better to pass the hook along the anterior inferior wall of the meatus, because owing to the inclination of the tympanic membrane its anterior inferior margin is much more deeply placed than its upper posterior part.

(ii) In the case of a hard substance, such as a piece of stone, coal, or a bead, blunt hooks may be used instead of sharp ones. They should be passed into the meatus beyond the foreign body in the manner already described.

(iii) In other cases, depending on its shape and position, the foreign body is better removed by means of a snare, the loop of which is manipulated round it and then drawn tight in the same manner as in the extraction of a polypus.

The chief points to observe in these manipulations are (a) not to push the foreign body farther in and (b) not to injure the walls of the meatus or the tympanic membrane.

Other methods of extraction are—(1) Drilling through the foreign body, if it is a hard substance, and then inserting a fine hook into the opening so made. (2) The agglutinative method, which consists in dipping a small paint-brush into a concentrated solution of seccotine or glue and then inserting it into the meatus until it comes in contact with the foreign body. The brush is left in this position for several hours in the hope that it may become adherent to the foreign body; if so, on withdrawing the brush from the ear, the foreign body should be extracted with it. This method can only be used provided the ear is kept dry.

These procedures, although said to be successful in a few cases, are not recommended.

After-treatment. If the tympanic membrane and auditory canal have not been injured, it is sufficient to dry the meatus and puff in a little boracic powder. If there be abrasions of the canal, a small strip of gauze should be inserted and changed as frequently as it becomes moist with secretion, the meatus, if necessary, being also syringed out with an aseptic lotion. If there be acute inflammation of the walls of the canal, accompanied by much swelling and purulent discharge, drops of glycerine of carbolic (1 in 10) may be instilled frequently. After the inflammation has subsided, an alcoholic solution of 1 in 3,000 biniodide of mercury may be employed. If the tympanic membrane has been injured, either from the presence of the foreign body itself or from the attempts at extracting it, the treatment is similar to that for an ordinary middle-ear suppuration.

Removal by operation. This may be done in the following ways:—

By means of a post-aural incision.

Indications. (i) If prolonged attempts to remove the foreign body by instruments have failed. This operation becomes imperative if there are signs of retention of pus within the middle ear.

(ii) If the foreign body has been pushed into the tympanic cavity and cannot be removed otherwise. In such cases, if the perforation is large and the foreign body is small, an attempt may first be made to dislodge the substance by injecting fluid into the middle ear through the Eustachian tube by means of the catheter and syringe (see p. 372). This method, however, is rarely successful.

Operation. The procedure is the same as for the removal of exostoses (see p. 318). After separating the fibrous from the bony portion of the canal, an incision is made through it and the cut edges are held aside with forceps. Usually the foreign body can now be seen lying within the canal. It is best removed by passing a small fenestrated curette beyond it and levering it out. In some cases one of the hooks already mentioned will be found to be more suitable. Forceps should not be used, as they may inadvertently push the foreign body farther in. If the foreign body be very deeply placed, removal of the upper posterior portion of the bony meatus may be necessary. The subsequent steps of the operation and its after-treatment are similar to that already described in the case of an exostosis.

By means of an operation upon the mastoid.

Indications. (i) If the above measures fail to remove the foreign body.

(ii) If there be symptoms of inflammation of the mastoid process, or of internal-ear or of intracranial suppuration.

(iii) If there be facial nerve paralysis the result of pressure from the foreign body.

Operation. The operation performed depends on the condition found. Simple opening of the mastoid antrum may be sufficient in a case of recent middle-ear suppuration, although it is usually necessary also to remove a considerable portion of the posterior wall of the auditory canal before the foreign body can be extracted. If these measures fail, an attempt may be made to dislodge the foreign body by forcibly syringing through the aditus, or by the insertion of a probe through it, into the tympanic cavity. If this likewise ends in failure, it will then be necessary to perform the complete operation. These cases fortunately are rare.

If it be certain that chronic middle-ear suppuration already exists, the complete mastoid operation is indicated.

If it becomes necessary to operate on the mastoid process, owing to other means having failed to dislodge the foreign body, it is wiser, as a rule, to perform the complete operation at once, because, under these circumstances, irreparable destruction must have taken place within the tympanic cavity.

The technique of these operations and their after-treatment are described in the chapter on operations upon the mastoid process (see p. 390).

OPERATIONS FOR STENOSIS OF THE EXTERNAL MEATUS

Stenosis, or stricture of the auditory canal, is practically always the result of traumatism or inflammatory conditions; it is only very rarely congenital.

Indications. (i) If there be deafness of the other ear, and the functionally good ear periodically becomes deaf from obstruction of the narrow passage by cerumen or epithelial dÉbris, and the patient is weary of conservative treatment.

(ii) If there be recurrent attacks of otitis externa.

(iii) If there be retention of pus, the result of inflammation of the external or middle ear, which is not relieved by conservative treatment.

The operation is contra-indicated if there is accompanying deafness, due to chronic middle-ear or to internal-ear disease, provided there is no suppuration within the external or middle ear.

Operation. The method of operation depends on whether the stricture is membranous, fibrous, or bony in consistence, or whether it is limited or is causing a general narrowing of the auditory canal. It may take one of the following forms:—

Dilatation. This method is not very satisfactory, and is limited to recent cases of membranous or fibrous stricture of the annular variety. After cleansing the meatus, a small laminaria tent is inserted through the stricture, and if the pain is not too severe it is left in situ for at least twenty-four hours and then withdrawn. The ear is again carefully cleansed, and if possible a larger laminaria tent is substituted. This procedure is repeated until the maximum amount of dilatation has been obtained.

Incision of the stricture. This also is limited to membranous or to fibrous strictures of the annular variety.

The operation, if necessary, may be performed under a local anÆsthetic, produced by subcutaneous injections, although usually a general anÆsthetic is preferable.

The ear and surrounding parts are surgically cleansed by the ordinary methods. The surgeon works by reflected light. The patient may be in either the sitting or the recumbent position, depending on whether a local or general anÆsthetic is given. In the latter case the auditory canal should be filled with cocaine and adrenalin solution before the anÆsthetic is administered in order to diminish bleeding as far as possible.

The ear having been dried, a conveniently large aural speculum is inserted, and with a tenotome or a furunculotome radiating incisions are made through the stricture. One of the small flaps thus made is grasped with a fine pair of tenaculum forceps, and the surgeon cuts through its base, keeping the knife as close as possible to the wall of the auditory canal. Each flap is treated in a similar fashion. Instead of making radiating incisions, the tissue forming the obstruction may be transfixed through its base, the knife being made to cut in a circular fashion right round the auditory canal, keeping as close as possible to its wall.

On completion of the operation, a piece of india-rubber tubing, of as large a size as possible, is inserted into the dilated canal. It should only be removed for the purpose of cleansing and should be at once reinserted. A silver canula, if necessary, can afterwards replace the india-rubber tubing. This canula may have to be worn for months.

This operation is often most unsatisfactory, as the stricture, instead of being annular as first supposed, may be found, on operation, to extend a considerable distance along the auditory canal and, in addition, to be partially due to a general thickening of the underlying bone.

Excision of the stricture. The auricle is reflected forward and the preliminary steps of the operation are performed as already described for removal of a deep-seated exostosis (see p. 319). The surgeon makes a transverse incision with a knife through the fibrous portion of the auditory canal, just external to the stricture, and carries it right round the meatus, thus separating the outer portion of the membranous from the bony canal. The fibrous portion is now pulled outwards by means of a retractor, and the thickened tissue, forming the stricture, is peeled off from the surrounding bony meatus with a small periosteal elevator and so removed. If the stenosis is partially due to thickening of the walls of the canal itself, it may also be necessary to chisel away a considerable portion of its upper posterior part. After completion of the operation a clear view of the tympanic membrane should be obtained.

In this operation a considerable portion of the bony canal is denuded of its epithelial lining membrane, so that there is a special tendency to the re-formation of cicatricial tissue. To prevent this taking place two methods may be employed:—(1) If much of the upper posterior wall of the bony meatus be removed, a post-meatal flap should be made and kept in position by means of a catgut suture carried through the skin behind the auricle. The formation of such a flap is described as a step in the complete mastoid operation (see p. 401).

(2) If no bone be removed, the membranous portion is replaced in situ, the posterior auricular wound closed, and as large an india-rubber tube as possible is inserted into the meatus. A week or ten days later, as soon as granulations begin to form, skin-grafting may be undertaken (see p. 410).

If grafting be not successful, the india-rubber tube or silver canula must be kept constantly within the meatus (only being removed for cleansing purposes) until healing takes place.

The complete mastoid operation is indicated in the case of stenosis occurring in chronic middle-ear suppuration if symptoms of retention of pus occur.

In acute middle-ear suppuration, however, every attempt should be made to avoid operation, as the lumen of the auditory canal may again become patent after the acute inflammation has subsided.

OPERATIONS FOR ATRESIA

Atresia of the external meatus may be either congenital or acquired.

Indications. (i) In congenital cases operation is only justifiable if the atresia is due to a membranous web situated in the outer part of the auditory canal and if, as a result of tuning-fork tests and of inflation through the Eustachian tube, it is fairly certain that the middle ear is normal.

Operation is contra-indicated in cases of bony atresia. Although attempts have been made to make an artificial canal in order to restore the hearing power, a successful result has not yet been obtained. Apart from the difficulty of retaining the patency of any canal so made, the accompanying malformation of the middle ear renders a successful result impossible (Paper by author, Journal of Laryngology, &c., March, 1901). Although the tympanic membrane is said to have been exposed by operation in a few cases, experience has shown that the supposed tympanic membrane was really the capsule of the temporo-maxillary joint.

(ii) In acquired cases operation is indicated if the other ear is deaf; if the site of the occlusion of the auditory canal is in its outer part and is due to membranous or fibrous tissue, and if there is no previous history of middle-ear disease, and if the labyrinth is still intact.

Operation is not advised if the other ear is normal, unless the patient particularly desires it.

Operation is contra-indicated if there is internal-ear deafness on the affected side and if the other ear is normal; or if there is a definite history of the closure of the auditory canal having been the result of a previous middle-ear suppuration. In the latter case the destructive changes within the tympanic cavity will be so marked that the chances of improving the hearing will be very slight in spite of the most successful operation.

Operation. If the obstruction be due to a fibrous band, an attempt may be made to remove it by excising it by the intrameatal method. In other cases the post-auricular method is necessary.

The chief point to remember is to make a large opening. For this reason the post-auricular method is to be preferred, as a considerable portion of the upper posterior wall can be removed and a large meatal flap fashioned (see p. 401).

Results. If the stricture or point of occlusion of the auditory canal is limited and composed of membranous and fibrous tissues, a good result can be usually obtained, and there is no reason why complete recovery of hearing should not take place if the labyrinth and tympanic cavity are normal.

Unfortunately, as in all cases of stricture, there is a tendency for it to recur.

OPERATIONS FOR AURAL POLYPUS

In this section only the aural polypi which project from the tympanic cavity into the external auditory meatus will be considered; whereas the treatment of granulations, and with them the minute polypi which are still limited to the tympanic cavity, will be discussed in the chapter on operations within the middle ear.

Indications. An aural polypus should always be removed because, apart from the fact that it is a symptom of underlying disease, it may obstruct free drainage of the purulent discharge, and therefore become a source of danger.

Operation. The simplest and the best method is removal by the snare.

In the case of small and soft polypi, the polypus is removed by traction—formerly called avulsion—after the snare has been tightened round its pedicle; with a large, tough, fibrous polypus considerable force may be required to tear through its pedicle. This procedure in the case of polypi arising from the region of the tegmen tympani has been known to give rise to fatal meningitis. In such cases the pedicle of the polypus should be cleanly cut through by the snare—so-called excision.

As aural polypi are always associated with suppuration, it is especially necessary that the ear should be thoroughly cleansed before operation.

A local anÆsthetic (see p. 310) is sufficient in the case of smaller polypi, but if the polypus be large and tough, it is wiser to give a general anÆsthetic, such as gas and oxygen. Or a 3% solution of cocaine may be injected into the growth, which, according to Frey of Vienna, renders removal absolutely painless; this, however, has not always been my experience.

The size of the polypus and the origin of its pedicle should be determined before operating, if necessary by using a probe (Fig. 181); also it must be diagnosed from a bulging congested tympanic membrane, or from the inner surface of the tympanic cavity, which may be exposed to view owing to complete destruction of the membrane having already occurred.

A Wilde’s snare is generally used. It is a fine angular snare fitted with soft copper wire. The loop of the snare should be bent downwards and forwards and should be of such a size as to just surround the growth. The snare is held between the thumb and the first and second finger of the right hand (Fig. 182). Under good illumination, and using the speculum and reflected light if necessary, the shaft of the snare is passed along the upper portion of the auditory canal until the edge of the polypus is reached. The loop is made to encircle the polypus (Fig. 183), the snare is gradually pushed inwards with a gentle sinuous movement until it reaches the point of attachment of the growth. The loop is then tightened until it firmly grasps the neck of the polypus (Fig. 184). The friable tissue is torn through by gentle traction and the polypus is withdrawn in the snare. Care must be taken not to injure the tympanic membrane through which the polypus may be projecting; it is for this reason that the loop is bent at an angle to the shaft of the snare so that it may lie parallel to the tympanic membrane whilst in the act of grasping the polypus. If the polypus be very small its pedicle may be clearly defined before operation, and the snare passed round it directly (Fig. 185).

If the polypus be very large and tough, the snare is made to cut clean through its pedicle as near to its attachment as possible, instead of employing traction. The snare is then withdrawn, the polypus being afterwards grasped and removed by means of forceps. In this latter case it may be necessary to use a stronger snare fitted with piano steel wire instead of the ordinary copper wire. On removal of the polypus there may be considerable hÆmorrhage. After it has ceased the ear is syringed out and dried. The auditory canal is then inspected, and if it is found that the growth has not been removed completely, this can be done now by reapplication of the snare.

After final cleansing of the meatus, a strip of gauze is inserted, and the ear protected with a pad of cotton-wool and a bandage.

After-treatment. The dressing should be removed within twenty-four hours, and the ear cleansed by syringing. After mopping it dry drops of rectified spirits should be instilled.

On removal of the first dressing, any polypoid tissue which remains may be cauterized under cocaine anÆsthesia by the actual cautery, or by a bead of chromic or trichloracetic acid (see p. 348).

Further treatment consists in keeping the ear clean and dry. For the first few days it should be syringed daily, dried, and spirit drops instilled. As the secretion becomes less the syringing should be diminished. If the perforation be large, instead of instilling drops, some finely powdered boric acid may be puffed in.

Other methods of removal. These are not recommended, but merely mentioned for the sake of completeness.

By forceps. The rough and ready method of extracting a polypus forcibly from the ear by means of forceps, although practised formerly, has now been discarded as being unsurgical and dangerous.

Ligation. The operation consisted in passing a snare over the polypus and grasping it tightly as near to its base as possible. The snare was then twisted round its axis in order to tighten the loop further and so obliterate the blood-supply of the growth, the wire of the snare being afterwards cut through with pliers and the snare withdrawn. After a few days the polypus became gangrenous from want of blood-supply, and separated from its deep attachments.

Curetting. This method, which should only be made use of in the case of small multiple polypi within the tympanic cavity, will be considered when discussing the treatment of granulations within the middle ear (see p. 398).

Dangers. HÆmorrhage is seldom profuse, but if it is, it can always be arrested by packing the meatus with cocaine and adrenalin solution.

The chief dangers are injury to the contents of the tympanic cavity, such as dislocation or removal of the ossicles; or subsequent meningitis. These mishaps are usually the result of forcible extraction, or of blindly curetting the ear after this has been done. Meningitis, however, has been known to occur, in spite of every precaution being taken, if, owing to caries of the tegmen tympani, the polypus has its origin from the dura mater of the middle fossa.

Prognosis. If the polypus be single and of recent origin, the result probably of acute inflammation of the middle ear, its removal may cause complete recovery and cessation of the middle-ear suppuration.

In the case, however, of multiple polypi associated with chronic middle-ear suppuration and usually signifying underlying bone disease, recurrences may be frequent and further operations may become necessary.

It may here be emphasized that a polypus in itself is not a disease, but merely a symptom of disease.

After removal of a large polypus, the patient should always be kept under observation for a day or two in case of symptoms of acute inflammation of the mastoid process arising and necessitating further operation.

CHAPTER III
OPERATIONS UPON THE TYMPANIC MEMBRANE AND
WITHIN THE TYMPANIC CAVITY

SURGICAL ANATOMY OF THE TYMPANUM

The tympanic membrane. The chief points to notice when operating on the tympanic membrane are its inclination and its relation to the inner wall of the tympanic cavity.

The normal membrane is inclined obliquely downwards and forwards so that it forms an obtuse angle of 140 degrees with the roof and an acute angle of 27 degrees with the floor of the external meatus. In infants the inclination is even greater.

Its relation to the tympanic cavity varies in its different parts. It lies nearest to the inner wall in the region of the umbo, being only 2 millimetres distant from the promontory, and is furthest from it in the posterior quadrant.

Running backwards, just below the posterior fold, is the chorda tympani nerve, which may be cut through in the act of paracentesis and in division of the posterior fold.

The tympanic cavity. For the purpose of description the portion of the tympanic cavity above the level of the tympanic membrane is known as the attic or epitympanic cavity; whilst the part below its level is called the cellar or hypotympanic cavity (Fig. 186).

The attic contains the head of the malleus and the body and short process of the incus, and communicates posteriorly with the antrum by a variable sized opening—the aditus. Its roof, the tegmen tympani, a plate of bone frequently of extreme thinness, separates the cavity of the middle ear from the middle fossa of the cranium. The facial canal extends backwards along the inner and upper border of the tympanic cavity, passing above the vestibule and the fenestra ovalis to curve downwards posteriorly beneath the external semicircular canal, which at this point forms the inner and inferior boundary of the aditus.

The ossicles form a movable chain fixed at three points: namely, the attachment of the handle of the malleus to the tympanic membrane; the posterior ligament of the incus, a feeble structure, binding its short process to the entrance of the antrum; and the strong annular ligament connecting the footplate of the stapes to the margins of the fenestra ovalis.

In addition, the anterior, external, and superior ligaments of the malleus also tend to keep it in position and limit its movements.

The tensor tympani muscle, extending from the processus cochleariformis, crosses the tympanic cavity to be inserted into the inner margin of the neck of the malleus; and the stapedius muscle emerging from the apex of the eminentia pyramidalis is inserted into the head of the stapes.

These ligaments and muscles partially divide the cavity into smaller compartments, such as the outer attic and Prussak’s space, so that in some cases inflammation may be limited to only a part of the tympanic cavity; a fact to be remembered in considering the question of operative procedures.

OPERATIONS UPON THE TYMPANIC MEMBRANE

PARACENTESIS

Indications. The chief object of paracentesis (myringotomy or simple incision) is to permit of escape of fluid from the tympanic cavity.

(i) In acute inflammation of the middle ear, if the acute symptoms continue in spite of palliative treatment, and the following conditions are present:—(a) An increasing congestion and bulging of the tympanic membrane, especially if accompanied by earache and pyrexia. (b) The obvious presence of pus within the tympanic cavity, shown by a circumscribed, angry red or yellow protuberance on the tympanic membrane. (c) Accompanying cerebral symptoms, such as drowsiness, vomiting, vertigo, and convulsions. (d) Tenderness over the mastoid process. (e) Paroxysms of pain acute enough to prevent sleep.

Paracentesis should be done early in infants and in specific fevers. In the former case even a slight middle-ear inflammation may give rise to all the cardinal symptoms of meningitis, which frequently subside rapidly as the result of simple paracentesis; in the latter, there may be rapid destruction of the drum, which a timely incision may possibly prevent.

(ii) In middle-ear catarrh with exudation. Paracentesis is justifiable in order to remove the secretion, if the hearing does not improve after a month’s treatment, owing to the existence of exudation within the tympanic cavity.

(iii) As a preliminary to intratympanic operations.

Operation. The auricle and surrounding parts are surgically cleansed (see p. 309), the preliminary toilet, if possible, being carried out at least half an hour before the operation is performed.

Although apparently a trivial matter, it is of the utmost importance to render the auditory canal as aseptic as possible in order to prevent secondary infection of the tympanic cavity from without.

It is wiser to give a general anÆsthetic, such as gas and oxygen, as the pain of the operation may be intense. If this is refused, local anÆsthesia by Gray’s solution (see p. 310) or by a subcutaneous injection of cocaine and adrenalin may be employed. In infants an anÆsthetic is not necessary.

The patient may be sitting up or lying down. If a general anÆsthetic has not been given, the patient’s head must be held firmly by an assistant in order to prevent sudden movement. The surgeon works by reflected light in order to obtain a clear view of the tympanic membrane.

The point of election for the incision is through the posterior part of the membrane, excepting when it is obvious from the bulging and appearance of the membrane that the incision must be made in the anterior inferior quadrant.

The incision is made by means of a paracentesis knife, which is shaped like a tiny bistoury set at an angle to its handle (Fig. 187). The double-edged spear-shaped knife is now seldom used, as with it there is a tendency to puncture rather than to incise the membrane.

The tympanic membrane is pierced by the paracentesis knife at its inferior posterior margin. With a quick movement the drum is incised freely, the incision being carried in an upward direction midway between the malleus and the circumference of the membrane posteriorly, until it reaches Shrapnell’s membrane (Fig. 188). In making this incision the inclination of the membrane must not be forgotten. Owing to its lower margin being more deeply placed than the upper, there is a tendency for those who have not had much practice in doing a paracentesis to begin their incision too high up, as they fail to realize the greater depth of the canal at this point. The soft tissues of the upper posterior wall of the external meatus close to the membrane, if much congested, may be incised also in the act of withdrawing the knife. In doing this the chorda tympani nerve may perhaps also be cut, resulting in loss of taste on the affected side for a time; this is a matter of no importance. As a result of this free incision, drainage is given to the contents of the tympanic cavity, attic, and antrum.

In order to prevent rapid closure of the perforation and to give better drainage, some authorities advise making a flap-shaped incision. To do this, the membrane is incised upwards, nearly to its upper border; the knife is then carried backwards and downwards before it is withdrawn from the wound.

Occasionally the acute inflammation is limited to the attic, Shrapnell’s membrane appearing deeply congested and bulging outwards so as to cover the processus brevis, whilst the rest of the membrane may be only slightly injected. In such cases it is sufficient to incise the bulging area, beginning the incision just above the region of the processus brevis and carrying it horizontally backwards to its posterior extremity (Fig. 189).

After-treatment. In acute middle-ear inflammation, after the first rush of blood and discharge has been mopped away, a small drain of sterilized gauze should be inserted into the auditory canal and the ear protected with a pad of sterilized gauze. The dressing and gauze drain should be changed as often as may be necessary, depending on the amount of discharge. The ear should not be syringed out unless the discharge becomes very profuse and thick.

In acute middle-ear catarrh with exudation, a Siegle’s speculum (Fig. 194) should be inserted into the meatus after free incision of the membrane, and as much fluid as possible extracted by suction. In addition, gentle inflation by means of Politzer’s method will help to expel from the middle ear the fluid, which should then be mopped out of the external meatus. This should be repeated daily.

Difficulties and dangers. The usual fault is to mistake the congested posterior wall of the external meatus for the membrane.

If the patient is not under an anÆsthetic, the incision may be made too timidly, the membrane being only scratched. The pain thus inflicted will cause the patient to jerk away the head and probably prevent the membrane from being incised freely. The incision, therefore, must be made in a bold and rapid manner. It is better to make the incision too free than too small.

Care must be taken not to plunge in the knife too deeply for fear of wounding the mucous membrane of the inner wall of the tympanic cavity. This may result in adhesions between it and the membrane.

Further, cases have been recorded in which a too violent incision has injured or dislodged the ossicles, or in which severe hÆmorrhage has occurred, presumably from puncturing the bulb of the jugular vein, which was projecting abnormally through the floor of the tympanic cavity.

The two chief causes of failure are insufficient drainage from too small an incision, which may necessitate a further operation, and secondary infection from without.

Results. In the majority of cases, provided free drainage is established, the discharge ceases and healing of the membrane takes place from within a day or two to four weeks, depending on the character of the case. If the symptoms continue it may become necessary to perform the mastoid operation (see p. 373).

ARTIFICIAL PERFORATION OF THE TYMPANIC MEMBRANE

The object of the operation is to equalize the pressure within the tympanic cavity and external meatus so as to enable vibrations of sound to be transmitted more readily by the membrane and chain of ossicles to the inner ear.

Indications. (i) In the case of an extremely calcified membrane which apparently cannot vibrate.

(ii) To relieve tinnitus or vertigo which appears to be due to an alteration of tension within the tympanic cavity, the result of an impermeable stricture of the Eustachian tube.

(iii) As a means of diagnosis. If the hearing be improved or the subjective symptoms relieved as a result of the artificial opening, then, if the perforation closes (as it probably will do), the surgeon is in a position to suggest some more radical measure, such as ossiculectomy (see p. 351).

Operation. Two methods are employed: (i) The knife; (ii) The galvano-cautery. The perforation should be made in the postero-inferior quadrant.

In favour of the galvano-cautery is the fact that the perforation does not tend to close so rapidly. On the other hand, considerable damage may be done unless it is applied with extreme care. For this reason it is wiser to operate under a general anÆsthetic, such as gas and oxygen.

If the paracentesis knife be used it is not sufficient to make a simple incision; a small triangular flap must be excised. The operation should be performed under good illumination. The paracentesis knife is inserted boldly through the membrane a little behind and above the umbo. The membrane is incised in an upward and slightly backward direction towards its margin; then downwards parallel to its posterior border; then horizontally forward, meeting the original point of the incision. The excised portion of the membrane is removed by seizing it with a fine pair of crocodile forceps, or by means of a fine snare, if it has not been completely detached.

The galvano-cautery is applied cold; when it is in contact with the drum, the circuit is closed so that the point of the cautery becomes red-hot. After the membrane has been burnt through it is withdrawn rapidly so as not to scorch the surrounding tissues. In using the cautery care must be taken to push it only just through the membrane for fear of injuring the inner wall of the tympanic cavity.

After-treatment. The after-treatment consists in protecting the ear by a strip of gauze, which is changed as often as may be necessary.

DIVISION OF THE ANTERIOR LIGAMENT

Indication. It is advised by Politzer in those cases of marked retraction of the drum in which inflation causes an immediate improvement in hearing, which, however, only lasts a short time. In several cases Politzer found the cause of this to be due to tension of the anterior ligament causing retraction of the malleus.

Operation. The anterior fold is divided with the paracentesis knife just in front of the processus brevis of the malleus. The knife is then introduced 2 millimetres inwards through the incision and made to cut in an upward direction as far as Shrapnell’s membrane (Fig. 190, C). This should divide the ligament.

If the operation be successful, improvement in hearing and also diminution of the subjective noises should take place.

DIVISION OF THE POSTERIOR FOLD

Indication. The same as for the anterior ligament. Owing to the increased tension of the upper posterior quadrant of the tympanic membrane, it is assumed that the movements of the malleus are diminished, and with this the hearing power. Seeing, however, that the prominence of the posterior fold is due to the projection outwards of the processus brevis as a result of the handle of the malleus having become indrawn with the membrane, it is difficult to understand how its division can possibly be a means of restoring the retracted membrane to its normal condition.

On the few occasions on which I have performed this operation, no improvement has followed. Others, however, maintain that it may do good in certain cases. This, perhaps, may be possible if it is combined with other intratympanic operations, such as division of the anterior ligament or of the tensor tympani muscle.

Operation. The paracentesis knife is inserted through the most prominent part of the fold and is made to cut through it from above downwards (Fig. 190, B). If this is successful, gaping of the cut edges takes place and the membrane assumes a less retracted position, and increased hearing and diminution of the subjective symptoms should occur on inflation and rarefying of air within the external ear.

INTRATYMPANIC OPERATIONS

General considerations with regard to intratympanic operations and their results. The chief difficulty, from a clinical point of view, is to determine beforehand the exact pathological changes which already exist within the tympanic cavity. For this reason the indications given with regard to operation are of necessity somewhat empirical. For example, retraction of the tympanic membrane may be due to closure of the Eustachian tube; to adhesions between it and the promontory; to contraction of the tensor tympani, of the anterior ligament, or of the posterior fold. An operation to remove only one of these causes may, therefore, be insufficient; the difficulty is to know what to do. Even if further operations are performed, the result may be negative owing to adhesions having taken place already between the ossicles themselves, or from binding down of the incudo-stapedial joint or of the stapes to the inner wall of the tympanic cavity. And apart from this, even if temporary benefit is obtained, the final result may be worse than that which existed before operation owing to the natural tendency for adhesions to re-form.

The prognosis is better in the case of post-suppurative conditions than in the non-suppurative ones.

Improvement by operation may be hoped for if a temporary increase in the hearing power, with diminution of the subjective symptoms, is obtained as a result of inflation; especially in those cases in which the malleus is only locally adherent to the promontory.

Generally speaking, however, these operations are not recommended, owing to the impossibility of being able to give a good prognosis, and therefore they can only be considered as experimental.

These operations are contra-indicated—(1) If there be internal-ear deafness.

(2) If the stapes (as shown by tuning-fork tests and GellÉ’s test) be ankylosed within the fenestra ovalis, especially in the case of otosclerosis.

(3) If the membrane be completely adherent to the inner wall at its upper posterior quadrant, especially if this is of long standing, as the stapes will almost certainly also be fixed by adhesions.

DIVISION OF INTRATYMPANIC ADHESIONS

The position and extent of the intratympanic adhesions vary exceedingly, and may be the result either of middle-ear catarrh or suppuration. The following conditions may be found:—

(i) Adhesion of the handle of the malleus to the promontory, the rest of the tympanic membrane being movable.

(ii) Adhesions between other parts of the tympanic membrane and the inner wall of the tympanic cavity, either by bridles or bands of fibrous tissue, or by the membrane itself being adherent over a large area.

(iii) Adhesion of the edge of a perforation to the inner wall.

(iv) Adhesions surrounding the articulation between the incus and stapes, and the stapes itself.

Indications. Operation is justifiable in the case of adhesion of the malleus to the promontory if the rest of the membrane is freely movable; if the membrane bulges outwards and there is temporary improvement in hearing on inflation; and if examination shows that the labyrinth is intact. This operation is all the more indicated if there is marked deafness on both sides: it should then be attempted on the worse side. If, however, the intratympanic adhesions are extensive, it is very doubtful whether an attempt to separate the free part of the membrane from the part adherent to the inner wall is worthy of consideration.

It must also be remembered that adhesions in the region of the stapes cannot be seen, unless a large perforation of the membrane already exists. Operation is then only justifiable as a last resource if there is extreme deafness accompanied by distressing subjective symptoms.

Operation. Unless the patient is very sensitive or nervous, local anÆsthesia is sufficient. It is more convenient for the patient to be sitting up in a chair than to be in the recumbent position. The surgeon works by reflected light. Before the operation is begun, the ear must be surgically cleansed and carefully dried.

(i) Adhesion of the handle of the malleus to the promontory. With a paracentesis knife the membrane is incised round the handle of the malleus (Fig. 191). A small sickle-shaped knife, fixed at right angles to its shaft, is then inserted through the incision (in front of or behind the malleus as may be most convenient to the operator) and is made to cut through the adhesions between the malleus and the promontory (Fig. 192). In order to make sure that this has been accomplished, a small ring-knife, such as is used in the operation of ossiculectomy, is passed round the tip of the malleus, between it and the inner wall of the promontory, and slight traction is then exerted in order to pull the handle of the malleus outwards from the inner wall.

Provided asepsis has been maintained, this small operation seldom gives rise to any inflammatory reaction. The after-treatment consists in inserting a strip of gauze into the auditory canal; if it becomes moist with secretion, it should be changed.

Many methods have been devised to prevent recurrence of adhesions, but few are successful. Amongst these are daily inflation of the ear by means of Politzer’s method or the catheter; the injection of oil into the middle ear; and the insertion of small pieces of celluloid between the malleus and inner wall of the promontory according to the method of Gomperz. Another method is to resect the handle of the malleus (Fig. 195). After being freed from the promontory as above described, the manubrium is cut through with a pair of fine scissors (Fig. 174) just below the processus brevis, and the lower fragment is removed by means of Sexton’s forceps (Fig. 193).

(ii) Adhesion between the membrane and the inner wall of the tympanic cavity. Siegle’s speculum should be used to determine the position and extent of the adhesions (Fig. 194).

There are two methods of operation:—

(a) In the case of bands forming a bridle between the tympanic membrane and inner wall, an attempt may be made to cut through them. This is done by incising the membrane with a paracentesis knife in front of or behind the adherent portion, and then inserting through this incision the sickle-shaped knife. By rotating it upwards or downwards, as the case may be, the bands forming the adhesions are cut through. If this has been successfully performed, and if the retraction of the membrane was solely due to these bands, the tympanic membrane will be found to be freely movable on diminishing the pressure of air within the external meatus by means of Siegle’s speculum.

(b) If the adhesions be extensive, the only method affording a chance of success is to separate the free portion of the tympanic membrane from the part adherent to the inner wall, leaving the latter in situ. To do this the membrane is incised with a paracentesis knife just beyond the margin of the adherent portion, the incision being carried right round the affected part. A tiny spatula, bent at right angles to its shaft, is then inserted through the incision and passed round beneath the movable portion of the membrane so as to free it completely (Fig. 192).

(iii) Adhesion of the edge of a perforation to the inner wall. If the middle-ear suppuration has only recently ceased, it may be sufficient to divide the adhesion with a small knife curved on the flat and afterwards force the tympanic membrane outwards by means of inflation through the Eustachian tube, and by rarefaction of the air within the external meatus. In the majority of cases, however, it is necessary to excise the adhesion, especially in the more chronic conditions. This is done by cutting through the movable part of the membrane just beyond the adherent portion (vide supra).

(iv) Adhesions surrounding the articulation between the incus and stapes, and the stapes itself. These adhesions can only be observed if a large perforation involves the upper posterior quadrant. Even then it may be anatomically impossible to see the stapes. The operation should only be performed if definite bands of adhesions can be seen. Sometimes, although rarely, it happens that such adhesions are present. If the incudo-stapedial joint be fixed to the inner wall of the tympanic cavity, the adhesions are separated from it by passing the knife between the joint and the inner wall. In order to cut through adhesions surrounding the base of the stapes, a small horizontal incision should be made along its upper margin, and also along the lower, if this is in view. This operation, however, is seldom of any value.

TENOTOMY OF THE TENSOR TYMPANI

Indication. The chief indication for this operation is marked retraction of the tympanic membrane, in a case of middle-ear deafness, in which there are no adhesions between the membrane and the inner wall of the middle ear, and in which it is assumed that the retraction is due to shortening of the tensor tympani muscle.

Operation. The first step of the operation is to incise the tympanic membrane with a paracentesis knife in a vertical direction just behind the margin of the malleus. At the same time the posterior fold can be cut through, if required, by continuing the incision upwards. Through the incision thus made Schwartze’s tenotomy knife (a very fine blunt-pointed instrument curved on the flat (Fig. 196)) is inserted, its point being directed upwards. The knife is pushed upwards until its shaft is on a level with the processus brevis. The handle is then rotated in a forward direction so that the sharp edge of the knife, which is kept close to the posterior border of the neck of the malleus, makes a circular movement forwards and downwards and thus cuts through the tendon of the muscle. If the knife has been too deeply inserted, the attempt to rotate the shaft forwards will be resisted by the projecting processus cochleariformis. To overcome this difficulty the shaft of the instrument is rotated backwards so as to raise the point of the tenotomy knife and thus free it; the instrument is then withdrawn slightly and the shaft again rotated forwards. The division of the tendon can be distinctly felt, and may be accompanied by a slight crackling noise; after this has been effected, the knife is rotated backwards and withdrawn through the incision in the tympanic membrane.

After-treatment. There is usually a slight effusion of blood within the tympanic cavity, but no special treatment is required beyond keeping the ear aseptic. Absorption takes place rapidly.

The result of the operation is disappointing. There is seldom any improvement with regard to hearing; a few cases, however, have been reported in which the attacks of vertigo have diminished in intensity.

TENOTOMY OF THE STAPEDIUS

Indications. They are limited.

(i) As the result of middle-ear suppuration the malleus and incus may become exfoliated. The theory has been advanced that the unopposed action of the stapedius muscle prevents free movement of the stapes in these cases, and for this reason tenotomy of its tendon is advocated.

This operation, however, should only be performed provided that the edge of the membrane is not adherent to the inner wall of the tympanic cavity, and there is no internal-ear deafness.

(ii) The operation is also performed as a preliminary measure to removal of the stapes (see p. 361).

Operation. The operation is simple, as the head of the stapes and the tendon of the stapedius muscle are usually within view in consequence of the destruction of the tympanic membrane. The ear is cleansed and dried, and the part rendered insensitive by the previous application of a pledget of cotton-wool soaked in cocaine solution. The tiny tendon is severed with a snick of the paracentesis knife, cutting through it from above downwards under good illumination.

Results. These vary; usually there is no improvement, but sometimes marked increase of hearing occurs. As the operation can do no harm and can be done without any inconvenience to the patient, it may be attempted subject to the restrictions given above.

REMOVAL OF GRANULATIONS FROM THE TYMPANIC CAVITY

Indications. Granulations should always be removed if conservative treatment fails.

Operations. (a) Cauterizing; (b) Curetting. The former method is employed when the granulations are very small and localized; the latter when they are multiple and larger.

Cauterization. The tympanic cavity is cleansed and rendered anÆsthetic (see p. 310). The auditory canal and tympanic cavity are then carefully dried. This is of importance in order to prevent scalding of the surrounding tissues during the act of cauterization. The ordinary electric cautery is used; only a weak current is necessary as the point of the cautery, of necessity, is very small. Under good illumination, the cautery is inserted cold along the auditory canal until it just touches the granulation. The circuit is then closed, and on the point of the cautery becoming white-hot, it is pressed against the granulation and then rapidly withdrawn from the ear. The current should not be shut off until the cautery is withdrawn, otherwise it will adhere, on cooling, to the tissues with which it is in contact, and on withdrawal will cause bleeding.

Instead of the electric cautery, the granulations may be touched with a bead of chromic acid fused on to a probe, or with a saturated solution of trichloracetic acid. The galvano-cautery has the greatest effect. Chromic acid has the disadvantage that unless it is very accurately applied it tends to affect a larger area than was possibly intended. Trichloracetic acid, although more localized in effect, is not so potent.

After-treatment consists in blowing in a slight amount of boric acid powder and keeping the ear dry.

Curetting. This is performed by means of small ring-knives (Fig. 178) or sharp spoons. They vary in size, and are either straight or bent in different directions to the shaft of the instrument. The instrument selected depends on the position and size of the granulation.

To minimize the hÆmorrhage, adrenalin may be added to the cocaine solution. The curette is made to encircle the granulation and cuts through its attachment with a firm movement, limited to the area of the granulation. Curetting should not be done in a haphazard fashion, but deliberately under good illumination. If bleeding occurs it must be arrested before further curetting takes place.

After-treatment. The ear is syringed out to remove any fragments of granulation tissue or blood-clot. It is then dried and a strip of sterilized gauze inserted. After twenty-four hours this is removed and drops of rectified spirits, if necessary containing ten grains of boric acid or a drachm of the perchloride of mercury lotion to the ounce, may be instilled into the ear three or four times a day.

Dangers. With due care none should occur. The following mishaps, however, have occurred from too violent curetting: (1) Injury or displacement of the ossicles; (2) internal-ear suppuration from dislodging of the stapes or injury to the promontory; (3) facial paralysis; (4) meningitis from injury to the tegmen tympani; (5) acute inflammation of the mastoid process.

Results. Provided that the granulations are localized and due to inflammation of the mucous membrane, a good result may be anticipated. If, however, there be underlying bone disease of the tympanic walls, or if the mastoid process be already affected, recurrences are usual, and further operative treatment may become necessary.

OPERATIONS UPON THE OSSICLES

DIRECT MOBILIZATION OF THE OSSICLES

The object of the operation is to improve the hearing by breaking down the fibrous adhesions with the tympanic cavity, which diminish the mobility of the ossicles.

Direct massage of the malleus. Indications. (i) As a therapeutic measure. If the malleus be adherent to the promontory and there is no improvement on inflation, but perhaps slight improvement as a result of pneumatic massage.

(ii) As a means of diagnosis. If temporary improvement takes place it may be assumed that the stapes is not absolutely fixed, and that the deafness is partly due to adhesions preventing movements of the ossicles, a condition which may point to the advisability of performing ossiculectomy in suitable cases.

Operation. The ear is rendered insensitive by means of cocaine or Gray’s solution (see p. 310).

The manipulation is carried out with a Lucae’s probe (Fig. 197). Within its handle is a spring to render its movements resilient; and at its tip is a cuplike depression to embrace the point of the processus brevis of the malleus. The tip of the probe may be covered by a fine layer of cotton-wool or india-rubber.

The probe is inserted, under good illumination, into the auditory meatus and is applied to the processus brevis of the malleus. The vibrations are given by the rapid movements of the hand from the wrist, the arm being kept fixed. This procedure, which may be painful, should not last longer than one minute. Frequently there is considerable reaction, shown by congestion about the processus brevis and Shrapnell’s membrane. It is therefore wiser not to repeat the procedure at shorter intervals than one week.

Results. It is difficult to foretell what the result will be, as it is chiefly dependent on the extent of the adhesions already existing within the tympanic cavity and on the mobility of the stapes within the fenestra ovalis. If the latter is already fixed, then improvement is impossible. If, however, the adhesions are limited, a better result may be obtained by this method than by pneumo-massage and inflation. The surgeon must be guided by the extent and duration of the improvement as to how long to continue the treatment. Unfortunately, relapses are not uncommon, though temporary benefit may be obtained.

Massage of the stapes. This is only done as a last resource in the hope of obtaining some improvement in hearing.

Indications. (i) In cases in which mobilization of the malleus has caused no improvement, and it is hoped, from the history of the case, that this is due to fibrous adhesions fixing the stapes within the fenestra ovalis. This condition must be carefully distinguished from otosclerosis or bony ankylosis of the stapes, in which latter conditions any such procedure is absolutely contra-indicated.

(ii) Direct mobilization may be undertaken as a preliminary step previous to removal of the stapes itself. If the stapes is movable and slight improvement occurs, then its removal may be justifiable under certain conditions. If, however, the stapes is fixed and no improvement occurs, then its removal will be attended with such difficulty as to almost negative this being attempted.

Operation. If a perforation of the upper posterior quadrant be present, a small pledget of cotton-wool soaked in a 20% solution of cocaine is brought into contact with the inner wall of the tympanic cavity. After a few minutes Lucae’s probe is placed in position against the head of the stapes and the vibratory movements are carried out. If no perforation of the drum exists, then it is first necessary to excise a flap in the upper posterior quadrant of the membrane.

Difficulties. The chief difficulty is anatomical. Projection forward of the upper posterior part of the tympanic ring or a deeply placed niche of the fenestra ovalis may prevent a view of the stapes.

If the membrane has to be incised, the slight amount of bleeding may also prevent a good view being obtained.

There is no actual danger in the operation, but if the stapes is fixed or if much force is used, it is by no means difficult to fracture the crura of the stapes.

REMOVAL OF THE OSSICLES

Except under the most rare conditions only the malleus and incus are removed; the stapes, if possible, being left undisturbed.

These operations will therefore be considered separately.

Removal of the malleus and incus. This operation was first proposed by Schwartze in 1873, and later by Kessel, Ludewig, Sexton, and Zeroni.

Indications. The indications for operation may be considered with regard to (1) chronic middle-ear suppuration and (2) non-suppurative middle-ear disease, whether the result of a previous middle-ear suppuration or of a chronic middle-ear catarrh.

In chronic middle-ear suppuration, the chief object of the operation is to ensure drainage and if possible to remove the cause of the suppuration; in non-suppurative conditions, to improve the hearing.

It may here be mentioned that the position of the perforation in the attic region is frequently of importance when considering the question of treatment. If situated in front of the malleus, the disease is probably limited to the outer attic region and malleus; if just behind the malleus, then probably both the malleus and incus are affected; but if the perforation extends farther back, involving the upper posterior quadrant of the drum, especially its bony margin, it suggests disease not only of the ossicles together with the walls of the aditus and antrum, but perhaps also of the mastoid process (Fig. 198).

(i) In chronic middle-ear suppuration. Before operation is considered, it is presumed that conservative measures, such as syringing, instillation of astringent and antiseptic drops, and washing out of the attic by means of Hartmann’s canula with various solutions, have been given a thorough trial and failed.

(a) If the suppuration be limited to the attic region (although the main portion of the tympanic membrane is intact), provided there is marked deafness and there are symptoms of lack of free drainage indicated by recurrent attacks of headache, a feeling of heaviness or giddiness, or pain radiating up the head on the affected side.

(b) If there be caries of the malleus and incus, and the outer attic wall, with recurrence of granulations after repeated removal, especially if accompanied by cholesteatomatous formation, provided there is no evidence of disease of the mastoid process itself.

(c) Although the general symptoms and the condition found on examination justify the complete mastoid operation, yet if the patient refuses to have this operation performed, the simpler operation of ossiculectomy may be undertaken if desired. This will permit of free drainage and diminish the risk of future intracranial complications. It should, however, be clearly explained to the patient that no guarantee can be given with regard to effecting a permanent cure as a result of this operation.

(ii) In non-suppurative conditions.

(a) If there be marked middle-ear deafness, the result of adhesions, and the malleus is fixed to the promontory. Operation is justifiable if it is found that after each inflation of the middle ear, improvement of hearing is obtained which, however, is not permanent but only temporary.

(b) If, as the result of artificial perforation, made under the conditions already laid down, improvement takes place temporarily, but a relapse occurs from closure of the perforation (see p. 340).

(c) If tinnitus and attacks of vertigo, due to marked retraction of the membrane, are temporarily relieved by inflation. In this case operation should only be carried out as a last resource after all other measures have failed to cure and if the symptoms are very severe and distressing.

(d) If there be marked middle-ear deafness with extensive adhesions on both sides and evidence points to the stapes being freely movable. The operation is justifiable, as an experiment, on the worse side.

Operation. The only operation to be considered is the intrameatal one. Stacke originally suggested a post-auricular incision, and reflecting the auricle forward, and, after removing the ossicle, to remove also the outer attic-wall by means of the chisel. This method, however, has now been given up as being too radical, but will be mentioned later on in connexion with the mastoid operation (see p. 397).

Unless contra-indicated, a general anÆsthetic should be given, as it is not always possible to foretell whether the operation will be difficult or easy. In addition it may be necessary to curette out granulations and also to remove the outer wall of the attic. Unless the patient is very insensitive, this is almost impossible under local anÆsthesia (see p. 311).

Before the anÆsthetic is given, the ear should be filled with a 5% solution of cocaine containing a 1 in 2,000 solution of adrenalin chloride in order to diminish the bleeding during the operation.

The field of operation is isolated from the surrounding parts by covering the head with a sterilized towel having an opening cut in it just sufficient to expose the auricle and meatus.

The following are the steps of the operation: (1) freeing the malleus from its attachments to the tympanic membrane, and from the inner wall of the middle ear, if adherent to it; (2) cutting through the tendon of the tensor tympani muscle; (3) removal of the malleus; (4) removal of the incus; (5) removal of the outer wall of the attic; (6) curetting out of granulations, if present. The method of operation varies slightly according to the condition found.

Removal of the malleus. In post-suppurative and non-suppurative conditions the chief cause of failure is the recurrence of adhesions, so for this reason it is wisest to remove the membrane as completely as possible.

With a paracentesis knife, the membrane is incised below and behind the malleus. The incision is then carried upwards along its posterior border to the posterior fold, then round the complete margin of the tympanic membrane and along the anterior fold and border of the malleus, so as to meet the original point of the incision. The knife is then reinserted just in front of the processus brevis and cuts through the anterior ligament in an upward direction; in a similar fashion the posterior fold is also cut through (Fig. 190).

The next step is tenotomy of the tensor tympani muscle (see p. 345).

The malleus thus freed can easily be removed by seizing its handle with a pair of Sexton’s (Fig. 193) or crocodile forceps (Fig. 179). In removing the malleus it is necessary to remember that its head is situated within the attic and therefore cannot be pulled out directly, but must first be drawn downwards until it is seen within the tympanic cavity. If this precaution be not taken, the neck of the malleus may be broken, leaving the head behind. If this takes place its extraction may be a matter of difficulty.

Instead of using Sexton’s forceps, the malleus may be removed by means of Wilde’s snare. This is the method advocated by Schwartze. After cutting through the tensor tympani muscle, the loop of the snare is threaded over the head of the malleus and guided upwards until it embraces its neck. The loop is then drawn tight so as to hold the malleus firmly in its grasp. The ossicle is extracted by first pulling it downwards (Fig. 199), so as to dislodge it from the attic, and then outwards (Fig. 200).

Another method of extracting the malleus, and in my opinion the one to be preferred, is by Delstanche’s ring-knife (Fig. 201). This instrument differs from the ordinary ring-knife in that the upper border of its anterior part is especially sharpened so as to form a fine cutting surface. After the malleus has been freed from the membrane by means of the paracentesis knife, Delstanche’s ring-knife is made to encircle its handle. It is then pushed gradually upwards, keeping as close to the posterior border of the malleus as possible, until it cuts through the attachment of the tensor tympani. In doing this the instrument will embrace the neck of the malleus (Fig. 202). This permits of sufficient leverage to extract the malleus by gentle traction in a downward and outward direction without danger of fracturing its shaft. If much resistance be felt, probably the tensor tympani muscle has not been cut through, and another attempt should be made to do this before trying further extraction. The advantage of this instrument is, that once the knife has encircled the malleus it should be possible not only to cut through the tensor tympani, but to extract the bone itself without the use of any other instrument. If Schwartze’s tenotomy knife be used, two tenotomy knives are required, one for the right and one for the left ear. Delstanche’s ring-knife is equally good for either ear.

Extraction of the incus. Although it is frequently stated that extraction of the incus is more difficult than that of the malleus, in reality it is the easier part of the operation as, unlike the malleus, it has no firm attachments.

After removal of the malleus all hÆmorrhage must be arrested and a view obtained of the inner wall of the tympanic cavity. If it be possible to see the long process of the incus and its articulation with the head of the stapes, the articulation should be cut through with a small sickle-shaped knife. The knife is inserted just in front of the long process of the incus and, keeping close to it posteriorly, is made to cut downwards and backwards, thus separating its connexion with the stapes. Frequently the long process cannot be seen, or it may indeed have already disappeared as a result of caries. Theoretically this delicate manoeuvre is performed in order to prevent injury or dislodgment of the stapes during the act of removal of the incus. From a practical point of view, however, it does not appear to make any difference whether the incudo-stapedial articulation is cut through or not.

A variety of instruments have been described for the purpose of removal of the incus. Ludewig’s incus hook (named after Ludewig, who was one of the first to draw attention to this operation) is still recommended by many as being the best. It consists of a solid curved hook, having a length of 5 millimetres and a width of 2 millimetres, bent at right angles to its shaft (Fig. 203). A pair of these are necessary, one for each ear; also several sets of different sizes may be required owing to the variation in depth, height, and roof of the attic region. I, however, prefer Zeroni’s (Fig. 204). This hook, instead of being solid, consists of a steel eyelet having a backward curve similar to that of Ludewig’s.

The technique is the same whichever pattern is employed. The instrument is inserted in such a fashion that the hook is directed upwards, having its concavity backwards. It is passed into the attic at the point previously occupied by the head of the malleus. The shaft of the instrument is then rotated backwards so that the hook passes over the body of the incus (Fig. 205). As the rotatory action is continued downwards and finally forwards, the incus is dislodged from its position and forced into the tympanic cavity. It can now be seized by a pair of Sexton’s or crocodile forceps and removed. If it falls into the floor of the tympanum, it can usually be dislodged by syringing, or else by means of a small hook passed in circular fashion along the floor of the cavity.

Removal of the outer wall of the attic. In the majority of cases of chronic middle-ear suppuration, it is advisable to remove the outer wall of the attic in addition to performing the simple operation of ossiculectomy. If granulations be present they should first be removed, in order to give a clear view of the inner wall of the tympanic cavity, which can usually be obtained, owing to the fact that a large perforation of the membrane is probably present. The malleus and incus are then removed.

To remove the outer wall of the attic a small but strong pair of punch-forceps is required (Fig. 206). The instrument is directed along the roof of the auditory canal, its cutting edge held upwards and the blades kept slightly open, until the outer blade is felt to pass over the outer wall of the attic. The handle is then depressed so that the end of the forceps is forced upwards and embraces the outer wall between its points (Fig. 207). This is confirmed by attempting to withdraw the forceps, which the outer bony wall of the attic will now prevent. The position of the forceps being assured, its blades are brought together by pressure on the handle, and in this manner a small portion of the bone is punched out. In this way the outer wall of the attic is gradually cut away in small fragments. Sometimes this is extremely easy, owing to the auditory canal being large and the outer wall of the attic being thin and easily cut through. In other cases, owing to the thickness of the bony walls or to the narrowness of the canal, it is extremely difficult. If the outer wall of the attic has been completely removed, a fine probe, whose point is bent upwards, can be inserted into the attic and then withdrawn without encountering any obstruction, owing to the roof of the attic and outer wall of the auditory canal being now continuous. In some cases this part of the operation may not be necessary, as the outer wall of the attic may have already disappeared as a result of the caries.

Into the larger opening thus made, small curettes are passed upwards and backwards and any granulations in the region of the aditus and entrance to the antrum are curetted away. Finally the cavity is thoroughly swabbed out with the pledgets of cotton-wool soaked in a 1 in 2,000 alcoholic solution of biniodide of mercury. The cavity is then dried and a small drain of sterilized gauze inserted within the auditory canal, the ear being afterwards covered with a pad of gauze kept in position by a bandage.

After-treatment. In cases of non-suppuration there is rarely any pain, and if asepsis has been maintained, there is seldom much discharge beyond slight sanious oozing. Unless there is considerable discomfort the dressing need not be changed for two or three days. If possible the ear should not be syringed, but merely mopped out with pledgets of cotton-wool moistened with boric lotion and then dried, the gauze drain being afterwards inserted. This process may be repeated daily until healing is complete.

In middle-ear suppuration there may be considerable pain, owing to the forcible bruising of the tissues of the inner part of the auditory canal during the act of removal of the outer wall of the attic. Sometimes, indeed, there is much swelling of the lining membrane of the canal, with the occurrence of furuncles as the result of septic infection.

If there be no pain, the after-treatment is the same as above described, excepting that it may be necessary to syringe out the ear at each dressing owing to the discharge. If there be much pain, with swelling of the canal, the gauze drain should be removed and a 10% solution of carbolic acid in glycerine frequently instilled into the meatus. Subsequently drops of rectified spirit may be substituted.

Difficulties. 1. If the auditory canal be very small there may not be sufficient room to insert the instruments through the speculum. In such cases, if there be no middle-ear suppuration, it is wiser to leave the condition alone. If, however, suppuration exists, either the conservative treatment must be continued or the complete mastoid operation recommended.

2. HÆmorrhage, especially on curetting away the granulations, may be sufficient to prevent a view of the deeper parts. It can, however, usually be arrested quickly by plugging the auditory canal with gauze soaked in adrenalin and cocaine solution. Even if the surgeon has to wait a few moments, this must be done, as it is very necessary to obtain a clear view of the field of operation.

3. Extensive adhesions between the membrane and inner wall may render it difficult to separate the shaft of the malleus without fracturing its neck.

4. In old-standing cases in which there is a large perforation of the membrane, the malleus may be so retracted as not only to be difficult to see but difficult to seize. In this particular case, division of the tensor tympani with Schwartze’s tenotome and then extraction of the malleus by means of Sexton’s forceps is a better procedure than trying to encircle its shaft with Delstanche’s ring-knife.

5. Removal of the incus by the ordinary instruments may be rendered impossible owing to the narrowness of the attic posteriorly from chronic thickening of its walls. In these cases a seeker, such as Schwartze uses in the mastoid operation (Fig. 219), may be employed with advantage. It is passed over the incus in the same manner as an incus hook.

Accidents. 1. Fracture of the handle of the malleus. This is the result of too forcible extraction. If a Delstanche’s ring-knife has been used, this may be due to the tensor tympani not having been cut through; this should now be done. The head of the malleus is then removed either by means of a small hook or some form of curette bent at right angles to its shaft, depending on what is most suitable for the case in question.

2. Failure to extract the incus. In the course of a chronic middle-ear suppuration, the incus may become exfoliated or gradually disappear as the result of caries. It does not therefore always follow that inability to extract the incus means that the surgeon has failed in his manipulations, although frequently this is the case, the instruments failing to extract the incus, or perhaps dislodging it into the mastoid antrum, a fact which is difficult to determine and may only be discovered if the subsequent performance of the complete mastoid operation becomes necessary.

3. Facial paralysis. This accident is usually due to the incus hook not being inserted high enough up, so that, instead of entering the attic, it presses on the inner upper border of the tympanic cavity, and on being rotated in a backward and downward direction, it follows the line of the facial canal (Fig. 208). If much force be employed the frail wall of the facial canal will be fractured or pressed in on the underlying facial nerve. It is very rarely, however, that the nerve is completely crushed or torn through, and therefore recovery almost invariably takes place.

The facial nerve may also be injured whilst curetting away granulations in the upper posterior part of the tympanic cavity.

4. Injury to or removal of the stapes. This very rarely occurs during the act of removal of the incus, but is generally the result of too violent curetting. If only the crura be broken off, it does not matter; but if the stapes itself be dislodged from the fenestra ovalis, the subsequent symptoms may be attacks of vertigo, nausea, and vomiting. As a rule these symptoms subside. If, however, the internal ear becomes infected (although judging from literature and my own experience this is of very rare occurrence), complete deafness or even meningitis may occur as the result of labyrinthine inflammation or suppuration.

Results. (a) With regard to arrest of the disease. If the disease be limited to the ossicles themselves and to the anterior and outer part of the attic, a favourable prognosis may be given. Complete cessation of the discharge and scarring over of the affected part may take place within a month, or after a much longer period.

If, however, the disease be more extensive and involves the walls of the attic posteriorly and the region of the aditus, as shown by the presence of a fistula or granulations, the prognosis is uncertain and continuance of the discharge and recurrence of the granulations may eventually necessitate the complete mastoid operation.

(b) With regard to hearing. In the case of chronic attic suppuration the hearing power may be increased to a distance of 12 feet off for conversation, provided the internal ear is not affected and the stapes is not fixed within the fenestra ovalis; occasionally the result is much better. On the other hand, the hearing power may be made worse.

In post-suppurative conditions, the prognosis is not so favourable, as frequently the stapes is already bound down by adhesions; this is the more probable in the case of chronic middle-ear catarrh. In both these conditions the operation should never be performed without first explaining to the patient that it is practically experimental. The chief cause of failure is the recurrence of adhesions, which even the most complete and careful operation cannot always prevent.

Removal of the stapes. This operation is still in its infancy and it is, as yet, impossible to express an opinion with regard to its success or failure, and therefore the indications laid down are only tentative.

The objects of the operation are: (1) to improve the hearing in cases of deafness presumably due to fixation of the stapes within the fenestra ovalis, and (2) to relieve symptoms of tinnitus and vertigo due to the same cause.

Before this operation is advised careful examination must be made in order to determine whether the labyrinth is intact, especially if the operation is undertaken with the view of improving the hearing.

Indications. (i) If there be ankylosis of the stapes on both sides, accompanied by marked deafness and distressing subjective symptoms, operation is justifiable on the worse side.

(ii) In a one-sided affection provided the subjective symptoms of noises and giddiness are so oppressive as to render the patient’s life unbearable. The operation, of course, must not be attempted unless every other form of treatment has failed.

Operation. The operation may be performed either through the meatus, or by reflecting forward the auricle by means of the post-aural incision, and chiselling away the upper posterior part of the bony meatus in the manner suggested by Stacke (see p. 397).

The choice of the operation depends principally on the existing anatomical and pathological conditions.

If the meatus be very narrow the intrameatal method may fail to bring the stapes into view. If, on the other hand, the meatus be wide and there be a large perforation, the result of previous middle-ear suppuration, the incudo-stapedial joint or the head of the stapes itself may be actually within the field of operation.

The intrameatal method. The patient should be fully anÆsthetized and the operation performed under good illumination. A portion of the tympanic membrane in its upper posterior quadrant is excised in order to bring into view the incudo-stapedial joint. The incision is begun just behind the handle of the malleus and is carried upwards and backwards in a circular fashion through the tympanic membrane along the posterior fold, and then downwards for a little distance along its margin. The flap so made either falls downwards, or can be pressed downwards so as to expose to view the inner wall of the tympanic cavity. With a small knife, curved on the flat, the incudo-stapedial joint is cut through. With a fine hook the long leg of the incus is dislocated forwards or backwards from the stapes. The head of the stapes will now be seen, with the tendon of the stapedius muscle running horizontally backwards. With a paracentesis knife, the tendon is cut through close to its attachment to the stapes.

A fine, blunt-pointed hook is now inserted between the crura of the stapes. If the stapes be not firmly ankylosed it can usually be removed by slight traction. If, however, it be firmly fixed, its crura will probably be broken. To determine whether the stapes is ankylosed or not, direct pressure of the probe on the head of the stapes may be necessary. If the head of the stapes cannot be seen, it is advisable, as suggested by Dench of America, to punch out part of the upper posterior margin of the attic-wall with the attic forceps (see p. 357).

The post-aural method. The preliminary steps of the operation are the same as have been already described for removal of an exostosis (see p. 318).

After separating and reflecting forward the membranous from the bony portion, the upper posterior part of the tympanic ring is chiselled away until a view of the stapes can be obtained. The incus is then disarticulated from the stapes.

If the stapes be ankylosed by fibrous adhesions to the margins of the fenestra ovalis, an attempt may be made to free it by cutting through the adhesions with a fine bistoury. If this be impossible, a sharp hook may be fixed into the margin of the plate of the stapes in the hope of forcibly extracting it. Some authorities advise chiselling away of the margins of the fenestra ovalis. If an opening can be made into the vestibule by this means, it is hoped that the resulting scar tissue will form a membrane more resilient than the ankylosed stapes, and, in this way, permit vibrations of sound to enter the labyrinth. This operation, however, necessitates the complete mastoid operation in order to freely expose the region of the fenestra ovalis.

After-treatment. It is sufficient to protect the ear with a small gauze drain. Occasionally there may be considerable vomiting and vertigo as an immediate result of the operation; this usually passes off within two or three days. Meanwhile the patient should be kept in a recumbent position and, if necessary, given small subcutaneous injections of morphine.

Difficulties. The chief difficulty is to obtain a good view; even if this be obtained it is difficult to extract the stapes without fracture of its crura.

Dangers. As a result of opening up the labyrinth, one would expect considerable risk of infecting the internal ear. Judging from recorded cases, this, however, seldom occurs.

Results. The chief advocate of the removal of the stapes is Jack of Boston (Boston Med. and Surg. Journ., January, 1895), who again in 1902 (Archives of Otology, vol. xxxi, p. 407) stated: (1) that removal of the stapes did not destroy the hearing but sometimes improved it; (2) that the operation upon cases of moderate deafness might give brilliant results but was also attended with some risk to the hearing; (3) that the operation on the profoundly deaf was not advisable, as usually the stapes could not be removed owing to surrounding adhesions, and even if it were, no improvement was likely to occur owing to the sound-perceiving apparatus having probably already undergone irremediable changes.

Blake (Archives of Otology, vol. xxii), on the other hand, states emphatically that stapedectomy is harmful rather than beneficial.

The question, therefore, of removal of the stapes from the point of view of hearing is purely experimental. If there be bony ankylosis, it will be found impossible to remove the bone, and an attempt to do so will result in fracture of its crura. If, on the other hand, it be not ankylosed but movable, probably massage or, in cases of perforation of the tympanic membrane, direct mobilization of the bone will give results as good as those following stapedectomy.

The most favourable results are to be expected in those cases in which the operation is performed to relieve symptoms the result of previous middle-ear suppuration. In otosclerosis no benefit is ever obtained, and therefore the operation is absolutely contra-indicated.

On the other hand, there is ample evidence that the hearing power, in spite of removal of the stapes, may be retained. As an example may be quoted a case in which the stapes was removed accidentally in curetting out the ear after the removal of the malleus and incus, and in which I afterwards performed the complete mastoid operation owing to the continuance of the middle-ear suppuration. In spite of this, whispering could be heard at a distance of 20 feet (Journal of Laryngology, &c., vol. xxii, p. 33).

CHAPTER IV
OPERATIONS UPON THE EUSTACHIAN TUBE

Under this heading may be considered manipulations requiring special technical knowledge and skill: (1) Catheterization; (2) passing of bougies; and (3) washing out the tympanic cavity through the Eustachian tube.

CATHETERIZATION OF THE EUSTACHIAN TUBE.

Indications. (i) As a means of diagnosis in order to determine (a) the amount and character of the obstruction within the Eustachian tube; (b) the condition of the mucous membrane and whether any exudation is present within the middle ear.

(ii) For the purpose of treatment. (a) In order to instil medicated drops or vapours into the Eustachian tube and tympanic cavity; (b) as a preliminary measure to the passage of bougies into the Eustachian tube or to washing out the tympanic cavity through the Eustachian tube.

(iii) Catheterization is preferable to Politzer’s method if only one ear is affected. Politzer’s method, on the other hand, is preferable to catheterization (a) in small children; (b) in the case of slight middle-ear catarrh if both ears are affected; (c) if the passing of the catheter is very difficult and causes pain owing to nasal obstruction; (d) in nervous individuals who object to the catheter; (e) if the sudden inflation by means of Politzer’s method is more effectual than by catheterization.

Points to notice before inflation. 1. Care must be taken that the lumen of the catheter is not obstructed, and that the compressed air bag and auscultation tube are also in working order.

2. The nose must be cleansed of all secretion; if filled with crusts or in a septic condition, inflation must be avoided.

3. The patient should be sitting. Sometimes on inflation of the ear, especially for the first time, an attack of giddiness or faintness may occur.

4. The nose should always be examined to see that the passage is free. If it be obstructed catheterization may be impossible, or some special manipulation will be required in order to pass the catheter through the nose.

5. In order to prevent muscular contraction of the palatal muscles, which may grip the end of the catheter and so prevent its entrance into the orifice of the Eustachian tube, the patient should be told to breathe quietly and keep the eyes open.

A short silver or plated catheter is usually used. It is 5 inches in length and curved at its extremity. To indicate the position of the point of the catheter in the post-nasal space, a ring is attached to its outer and wider extremity corresponding with the concavity of the curvature of its beak (Fig. 209). The size of the catheter varies in diameter from Nos. 1 to 4 English size, that is, the same scale as used for urethral catheters. The source of compressed air used for the inflation is usually a Politzer bag having an india-rubber tube attached. At its end is a vulcanite pointed nozzle which accurately fits into the wider extremity of the catheter.

Technique. The patient is seated facing the surgeon, the head being supported by a prop or by an assistant. If the patient be at all sensitive, it is wiser to spray a very small quantity of a 2 or 5% solution of cocaine or eucaine into the nose, or, better still, to pass gently a probe tipped with a small pledget of cotton-wool soaked in the cocaine solution along the inferior meatus. This will effectively anÆsthetize the region of the pharyngeal orifice of the Eustachian tube, which is the most sensitive part.

The surgeon stands in front of the patient. The larger extremity of the catheter is held lightly between the thumb and first finger of the right hand, its beak being turned downwards, whilst the tip of the nose is tilted up by the thumb of the left hand (Fig. 210). In introducing the catheter into the nostril, the right hand is kept low down so that the stem of the catheter is almost in a vertical position. In this way the tip passes over the floor of the vestibule. As the catheter is gently pushed through the nose the right hand is raised so that the instrument assumes the horizontal position and passes backwards between the septum and the inferior turbinal, its beak being kept in close contact with the floor of the nose (Fig. 211). As the beak of the catheter enters the post-nasal space, it will be felt to glide over the soft palate.

With regard to the best method of introducing the beak of the catheter into the orifice of the Eustachian tube, opinions vary. Of the many methods advised only two will be given.

The first is more suitable to those who have not had much experience in using a catheter; the second is the one naturally adopted by an expert.

The first method. The catheter is pushed backwards until it is felt to impinge against the posterior wall of the naso-pharynx. The beak, which at this stage is directed downwards, is next rotated a quarter of a circle inwards so that it points horizontally towards the opposite side; the position is shown by the ring at its outer extremity (Fig. 212). The catheter is now gently withdrawn until the beak is felt to catch against the posterior edge of the vomer. During these procedures the stem of the catheter should rest on the floor of the nasal cavity. The manipulations are carried out with the right hand whilst the outer extremity of the catheter is kept fixed in position by means of the thumb and finger of the left hand.

The catheter is next pushed a short distance backwards to free it from the soft palate and rotated downwards, and finally round in an outward direction until the ring points to the outer canthus of the eye on the side to be catheterized (Fig. 213).

The point of the instrument should now engage the Eustachian tube; if, however, inflation shows this not to be the case the probability is that the catheter has been pushed too far backwards and rests on its posterior lip. This can be remedied by drawing it a little further outwards.

The second method. The catheter, with its beak turned downwards, is passed gently and rapidly along the inferior meatus of the nasal cavity, and at the same time rotated slightly outwards against the inferior turbinal bone. Whilst the catheter is within the nose, this outward rotation is prevented by the narrowness of the inferior meatus, but as soon as the beak of the catheter has passed behind the level of the inferior turbinal into the free post-nasal space, it will revolve outwards and upwards and in so doing will enter the Eustachian tube, which lies just behind and above the posterior end of the inferior turbinal bone.

Provided there be no abnormal obstruction within the nose, this method is an exceedingly simple one. With the practised hand the manipulation can be carried out so smoothly and quickly that the catheter will be in position before the patient has had time to realize the fact.

Difficulties. 1. Irritability of the mucous membrane. The passing of the catheter through the nose may set up a violent spasm of sneezing or coughing. When the beak has entered the post-nasal space, the irritation may cause such intense contraction of the palatal muscles that the point of the catheter may become fixed and its movement rendered impossible. If this takes place, the catheter should be withdrawn and the part anÆsthetized by means of cocaine and eucaine solution, which is best applied locally on a pledget of wool at the end of a probe.

2. Partial nasal obstruction. On inspecting the nose the obstruction is usually found to be due to a deviated septum or spur, or to adhesions situated at its anterior part. Sometimes a passage can be effected by simply diminishing the curve of the catheter. At other times the obstruction can be overcome by introducing the catheter with its stem held upwards and outwards, so that on entering the nose the beak dips in beneath the anterior end of the inferior turbinal. As the catheter is pushed gently inwards its outer extremity is brought round with a circular movement so that it gradually assumes the horizontal position. No force must be used. As the catheter is pushed farther in, it may rotate to a varying degree according to the formation of the nasal cavity. Sometimes, indeed, the catheter may make a complete rotation during its passage through the nose. At other times, after the obstruction is passed, the catheter is best pushed through the nose with the beak pointing directly upwards. The great point is gentleness; the catheter should be allowed to take whatever position suits it best, but after the beak has entered the post-nasal space the stem should lie horizontally along the floor of the nose and its beak should point downwards.

3. Complete nasal obstruction. If the obstruction be one-sided, then the catheter must be introduced into the nasal space through the opposite side.

This is performed in the ordinary manner, except that the catheter must be longer and possess a larger curvature. On reaching the post-nasal space, its beak is turned round so as to point towards the outer canthus of the eye on the affected side. It may be necessary to alter the curve more than once in order to get the point of the catheter to exactly engage into the orifice of the Eustachian tube.

If both sides be completely obstructed, the only method to adopt is catheterization from the mouth. The ordinary catheter is used. It is passed into the mouth, its beak being directed upwards, until it reaches the posterior wall of the pharynx. The catheter is then pushed directly upwards until its stem impinges against the soft palate. The beak is then turned outwards until it lies almost horizontally. In this position it should enter RosenmÜller’s fossa. The catheter is now withdrawn a little and should be felt to pass over a slight obstruction—the posterior lip of the Eustachian orifice. By gently pressing the beak slightly outwards, it should engage within the entrance of the Eustachian canal.

4. Obstruction within the post-nasal space. A common error in introducing the catheter is to push it too far backwards, so that on rotation of the beak outwards it passes behind the Eustachian tube and lies in RosenmÜller’s fossa. In this position the sounds referred to the examiner’s ear through the auscultation tube during the act of inflation differ from the normal sounds in that they are soft and distant. In a case of doubt inflation should again be practised with the catheter in varying positions. If the catheter be in the correct position, the patient should be able to talk without discomfort, and there should be no tendency to retching or coughing. If, however, the beak lies in RosenmÜller’s fossa, considerable irritation is caused, and on inflation the patient feels the air in the throat and not in the ear.

Catheterization may be rendered difficult by the presence of a large pad of adenoids or of a tumour; or inflation of air into the Eustachian tube may be quite impossible owing to the occlusion of its pharyngeal orifice, the result of scarring.

Mishaps. 1. Rupture of the tympanic membrane. With a normal membrane this is difficult to produce, in spite of even forcible inflation. Such an accident usually occurs at the site of some previous scar or atrophic patch in the membrane. If it occurs, there may be a temporary feeling of giddiness, noises, and pain in the ear. Inflation, of course, should be stopped at once and the ear protected for a day or two by plugging the meatus with a piece of cotton-wool.

2. Severe epistaxis. This is usually the result of trying to force the catheter through an obstructed nose, but it may also take place, though rarely, when manipulations have been carried out in a gentle fashion.

3. Syncope. This is fortunately of rare occurrence and usually only happens on the first occasion that the catheter is passed. For this reason the patient should always be in a sitting posture, and on the slightest appearance of pallor or faintness the catheter should be withdrawn. The attack invariably passes off, but for the moment it is very unpleasant.

4. Surgical emphysema. If the point of the catheter lacerates the mucous membrane, the air may be forced into the submucous tissue. This mishap, however, rarely occurs as the result of simple catheterization, but is more likely to follow forcible attempts to pass a bougie into the Eustachian tube.

PASSING OF THE EUSTACHIAN BOUGIE

Indications. This may be done for the following reasons:—

(i) As a means of diagnosis, to demonstrate the existence and position of a stricture.

(ii) To dilate a stricture.

(iii) As a therapeutic measure, to treat the mucous membrane of the Eustachian tube by means of a medicated bougie.

Bougies are made of various materials, but for ordinary purposes the gum-elastic is the best. They are about 7 inches in length with a slightly bulbous point.

In the adult the length of the Eustachian tube is approximately 1½ inches, of which 1 inch forms the cartilaginous and ½ inch the osseous portion. The narrowest part of its lumen is known as the isthmus, and is situated at the junction of its cartilaginous and bony portion. On passing the bougie through the catheter into the Eustachian tube, it is essential to know how far its point is projecting beyond the point of the catheter. For this purpose the bougie may be marked at its outer extremity. Five inches from the point of the bougie, that is, the same length as the catheter, is a black band a centimetre in length; a centimetre farther up is another black band; and again after an intervening space of a centimetre is a third black band (Fig. 214).

Technique. The catheter is introduced in the ordinary way, and its position within the entrance of the Eustachian orifice is verified by means of inflation. It is kept fixed with the left hand, and the bougie is pushed into the catheter until the beginning of the first mark on the former just reaches the outer extremity of the latter; the tip of the bougie will now be flush with the point of the catheter. If there be no pain and no resistance, the bougie is very gently pushed on until the beginning of its second black band just enters the catheter. Its point will now project 2 centimetres within the Eustachian tube; that is, to about the region of the isthmus. If the bougie has been successfully introduced into the Eustachian tube, the patient generally states that the instrument is felt within the ear itself. No force should be used for fear of making a false passage, and with gentle manipulation it is very rare for actual pain to occur. On reaching the isthmus resistance may be met with, but by the exercise of slight pressure the bougie can usually be made to pass through it; if there be much resistance the bougie should be withdrawn and a finer one substituted. After passing through the isthmus, the bougie may be pushed in another centimetre, but no further, in case it may actually enter and injure the contents of the tympanic cavity.

After the tip of the bougie has passed through the isthmus the surgeon will hear its movements through the auscultation tube as a rub or crackling sound. It is left in position for five or ten minutes and then withdrawn. The ear should then be gently inflated, when the air entry into the tympanic cavity will probably be found to be much more free.

As the passage of the bougie causes a certain amount of reaction, it should not be passed oftener than once a week. Although no force should ever be employed, the largest possible bougie should be passed at each successive sitting until complete dilatation has been obtained.

Difficulties. 1. If the catheter be not in position, the bougie may pass behind the tip of the Eustachian orifice and enter RosenmÜller’s fossa. This can usually be felt by the patient as a pricking sensation in the throat, and may produce retching and coughing.

2. A stricture of the Eustachian tube may be so great as to prevent entrance of the bougie.

Dangers. (a) Surgical emphysema. If the mucous membrane be lacerated by the bougie, air may be forced into the subcutaneous tissues on inflation, after its withdrawal. In some cases the surgical emphysema is so considerable as to involve the side of the neck and face, and indeed has been known to necessitate the performance of laryngotomy.

The best treatment is to make the patient suck ice and to forbid all attempts at blowing the nose and coughing. Sometimes it is also necessary to scarify the pharynx and soft palate with a small bistoury. Recovery may be hastened by gentle massage of the neck and face. Inflation should not be attempted again for at least a week.

(b) The bougie may be pushed in too far and cause injury to the contents of the tympanic cavity.

(c) The tip of the bougie may break off whilst in the Eustachian tube. With a gum-elastic bougie this is very rare, but it is more likely to occur if the brittle celluloid bougies are used. To prevent this unfortunate disaster the bougie should be carefully examined before passing it, to see that it is not cracked nor broken. If such an accident does happen it is wiser to do nothing, because as a rule the fragment is afterwards expelled spontaneously.

Results. If the obstruction be fairly recent and limited to the pharyngeal end of the Eustachian tube, excellent results may be obtained by using either the simple bougie or the catgut variety moistened with a 5% solution of silver nitrate.

Owing to the general thickening of the tube, there is a marked tendency for further stricture to take place in the more chronic cases, even if a temporary improvement is obtained, and for this reason the use of the bougie is seldom to be recommended.

WASHING OUT THE TYMPANIC CAVITY THROUGH THE EUSTACHIAN TUBE

Indications. (i) In chronic middle-ear suppuration in which the perforation is situated in the anterior inferior quadrant and the continuance of the otorrhoea is apparently due to the secretion not being able to drain from the tympanic cavity. This method may be employed to effect drainage and in order to cleanse the tympanic cavity thoroughly before the instillation of medicated drops. In these cases the floor of the tympanic cavity is usually at a considerable depth beneath the lower limit of the membrane (Fig. 186).

(ii) In order to remove a small foreign body lying on the floor of the tympanic cavity which cannot be expelled by syringing. The operation is only tentative and is seldom successful.

Contra-indications. (i) If there be acute middle-ear suppuration; (ii) if the perforation be very small, as there will be a considerable risk of the fluid being driven into the mastoid antrum and further infecting it.

Technique. A catheter of wide calibre is passed in the ordinary manner. Inflation is practised to see if it is in the right position. The left hand fixes the outer extremity of the catheter at its entrance within the nose and keeps it in position. The patient inclines the head over to the affected side and holds a receiver beneath the ear. A small brass syringe whose nozzle accurately fits the outer extremity of the catheter is used. Slight force may be required during the act of syringing, but must not be sufficient to cause pain within the ear. A certain amount of fluid always escapes into the throat although the catheter is in its right position, and this may set up an attack of retching and coughing. To avoid this the patient should incline his head slightly forward as well as to the affected side and breathe gently with the mouth open. If the manipulation be successful the fluid will trickle out of the external meatus.

A foreign body is rarely expelled by this method, as the force of fluid syringed into the Eustachian tube is seldom sufficient, and it is not wise to use too great pressure. In order to expel all the fluid from the tympanic cavity, the ear is afterwards inflated by Politzer’s method, and at the same time the fluid is mopped out of the ear by means of pledgets of cotton-wool.

Results. If the continuance of the middle-ear suppuration has been chiefly due to the retention of the purulent secretion in the lower part of the tympanic cavity, this method of treatment is frequently most satisfactory. In other cases no benefit is obtained owing to the suppuration being due to other causes.

Dangers. The chief danger is the infection of the mastoid cells.

CHAPTER V
OPERATIONS UPON THE MASTOID PROCESS: WILDE’S
INCISION AND SCHWARTZE’S OPERATION

With few exceptions the conditions requiring operative procedures on the mastoid process are the result of some suppurative lesion which has originated within the tympanic cavity.

The object of such operations is to arrest or eradicate the disease which, by further extension through the bony walls of the temporal bone, might eventually cause death by giving rise to some suppurative intracranial complication.

For their successful performance a knowledge of the anatomical relationships of the mastoid process is essential. It is sufficient here to remind the reader of the main surgical points in this connexion (Fig. 215).

SURGICAL ANATOMY OF THE MASTOID AREA

The mastoid antrum. At birth the mastoid antrum is almost fully developed. In infancy it is situated superficially and at a much higher level in relation to the auditory canal than in the adult. In the infant, also, the petro-squamous and the squamo-mastoid suture are still patent. As the mastoid cells develop, the antrum gradually becomes more deeply placed, so that in the adult it is from half to three-quarters of an inch from the surface.

Its roof, the tegmen tympani, is continuous with that of the attic. Anteriorly it is separated from the external auditory meatus by the posterior wall of the auditory canal, whose innermost margin forms the outer wall of the aditus. On its inner wall lie the semicircular canals, whilst posteriorly the lateral sinus is separated from it by an intervening layer of mastoid cells or compact bone. Between the semicircular canals and the lateral sinus is a small area composed of a thin layer of bone, separating the antrum from the posterior fossa of the cranial cavity.

The mastoid process. In the infant this is undeveloped and is merely represented by a small bony protuberance. By the fourth year it has practically reached the adult type.

Anatomically the mastoid process can be subdivided into three chief types: (1) the pneumatic, in which the cells are few and large; (2) the diploic, containing numerous small cells; and (3) the compact, in which the bone is extremely dense. Mixed types are frequently found, the cortex, as a rule, being more dense than the deeper portion. Occasionally it is uniformly sclerosed, almost of the consistence of ivory, but in these cases the condition is usually pathological, the result of chronic inflammation of the mastoid process.

The mastoid cells converge towards the antrum and may be divided into two groups: (1) those extending vertically downwards to the tip of the mastoid process; and (2) those lying between the antrum and the sigmoid process of the lateral sinus. In addition to these two groups, it must not be forgotten that cells may extend in other directions; for instance, (a) anteriorly, along the root of the zygoma; (b) posteriorly, communicating with the cells of the occipital bone; (c) inferiorly, between the floor of the tympanic cavity and the jugular fossa; (d) internally, spreading inwards towards the apex of the petrous bone and surrounding the labyrinth; or (e) enveloping the orifice of the Eustachian tube.

The facial nerve, after dipping beneath the external semicircular canal, passes vertically downwards through the mastoid process to emerge at the stylo-mastoid foramen. Entering this foramen and running along the canal are the stylo-mastoid branches of the posterior auricular artery. These vessels, if cut through by the chisel, may bleed in a marked manner, thus drawing the attention of the operator to the fact that he is in close proximity to the facial canal and nerve.

Surface anatomy. Although it is impossible to foretell with certainty before operation what the anatomical structure of the mastoid process may be, yet some information may be gathered from the formation of the skull.

In the dolichocephalic type, the mastoid process is broad and frequently contains large cells, especially at its tip and round the lateral sinus, which is usually deeply placed. In the brachycephalic type, on the other hand, there is a greater tendency for the mastoid process to be narrow and to consist of dense bone, for the middle fossa to extend low down and to overlap the outer wall of the antrum, and for the lateral sinus to project forward and superficially, even to within 2 or 3 millimetres of the posterior border of the external meatus.

The posterior root of the zygoma may be considered approximately the line of demarcation between the roof of the antrum and mastoid process, and the floor of the middle fossa of the skull. This, however, is only a rough guide, as in some cases, especially of the brachycephalic type, the middle fossa may dip below this point. If this ridge is not well marked, then Reid’s base-line must be taken as the guide.

Just behind the auditory meatus, at its upper posterior margin, is the spine of Henle, which forms the anterior boundary of the suprameatal triangle. Macewen, who first described this triangle, gave it as a guide for the exposure of the antrum. Experience, however, has shown that no reliance can be placed on this as a landmark, as, if the bone is chiselled through at this point, it is by no means uncommon to expose the dura mater of the middle fossa. A point 10 millimetres (two-fifths of an inch) behind the spine of Henle corresponds to the anterior border of the sigmoid sinus. Behind the suprameatal triangle and beneath the zygomatic ridge is the body of the mastoid process, which has a smooth surface and is perforated by small foramina through which pass tiny vessels.

The antrum, in the adult, is situated at a slightly higher level than the tympanic membrane, its floor roughly corresponding with a line drawn horizontally backwards through the middle of the posterior wall of the bony meatus.

HISTORY OF THE MASTOID OPERATION

Although opening of the mastoid process as an operative measure dates back to the eighteenth century, yet Schwartze, in 1873, was the first to establish the operation as a practical procedure.

Schwartze’s operation consisted in the simple opening of the antrum and mastoid cells, leaving the middle ear untouched. This procedure was carried out no matter whether the disease was recent or long standing. It soon became recognized, however, that this operation did not effect a cure in all cases, more especially in those in which the disease involved the walls of the tympanic cavity.

KÜster, in 1889, suggested removal of the posterior wall of the external auditory meatus, and about the same time von Bergmann advocated removal of the outer attic-wall. The KÜster-Bergmann operation, first practised by Zaufal, may therefore be considered to be the origin of the complete mastoid operation.

Stacke’s name is frequently though wrongly mentioned in association with the complete operation, which is sometimes termed the Schwartze-Stacke operation. Stacke’s operation was devised with a view to removal of the ossicles and outer wall of the attic in those cases in which the bone disease was limited to these regions. This operation, however, is occasionally of service in the performance of the complete mastoid operation (see p. 397).

Thus the year 1889 may be considered as the starting-point of the complete mastoid operation. Since that date many modifications have been introduced, the majority of which are not worthy of reference.

After the technique of the operation had been developed and practised for some time, more careful attention was directed to the after-treatment. In the earlier days of the radical operation it was the rule to leave the wound open and to plug it with gauze, or to insert a drainage tube which was carried through the membranous portion of the external meatus.

The next step was the making of post-meatal skin flaps, with closure of the posterior incision and packing of the wound through the auditory canal; and the names most prominently associated with this are Panse, KÖrner, and Stacke.

Still more recently, in order to shorten the after-treatment, the wound cavity has been skin-grafted by the method first suggested by Siebenmann and afterwards amplified by Charles Ballance.

The operations which will be considered are:—

1. Wilde’s incision.

2. Opening of the mastoid process and antrum.

3. The complete or radical mastoid operation.

Although definite indications for the above operations will be given, it must be remembered that in many cases the extent of the operation will depend very largely on the pathological condition found during the course of the operation itself, as frequently the clinical symptoms are not sufficient to determine beforehand what operation is indicated.

In comparing the simple opening of the mastoid cells and antrum with that of the complete or radical operation, the fundamental difference is that in the former the tympanic cavity and its contents are not interfered with, whereas in the complete operation the middle ear, antrum, and mastoid cells are converted into one large cavity. In consequence, complete recovery of hearing may take place in the former case; in the latter, however, this is not possible.

Although these operations, especially in the more acute conditions, are performed from the point of view of saving the life of the patient, due regard must also be given to the preservation or restoration of the hearing power, if this indeed is possible. If the hearing power be very poor, that is, if conversation cannot be heard more than 12 feet off, and especially if the deafness be partially due to changes having already taken place within the labyrinth, then the complete operation is to be preferred if it be doubtful whether Schwartze’s operation will be sufficient to eradicate the disease. If, on the other hand, the hearing power of the affected ear be fairly good, and with this there is deafness of the opposite side, then, unless it is absolutely essential that the complete operation should be performed, an attempt should be made to effect a cure by the simpler operation, provided it is first explained to the patient that it may perhaps be necessary to perform the complete operation afterwards.

WILDE’S INCISION

In cases of acute inflammation of the mastoid process or of a subperiosteal abscess lying over it, Wilde made a post-aural incision, incising the tissues down to the bone. The indications for doing this are now considered to be very few, but it must be remembered that in Wilde’s day the mastoid operation had not been developed.

Indications. (i) In infants it is sometimes justifiable, as the pus may have escaped to the surface of the mastoid process either through the squamo-mastoid suture or along the posterior wall of the auditory canal, between the periosteum and bone, without there being any actual disease of the bone.

(ii) As a temporary measure, to permit of drainage of a subperiosteal abscess, if the operation on the mastoid process cannot be performed for twenty-four hours or more.

(iii) In acute middle-ear suppuration a free incision down to the bone may relieve the pain if there are symptoms of periostitis of the mastoid process; it is, however, rarely necessary.

Contra-indications. In older children and adults (with the above exceptions) this operation is not sufficient, as the periostitis or subperiosteal abscess over the mastoid process is secondary to underlying bone disease which can only be eradicated by an operation on the mastoid process itself. Although healing may apparently take place, fistulÆ or other evidences of mastoid disease almost invariably occur afterwards.

Operation. In an infant a general anÆsthetic is not necessary, but in an adult gas anÆsthesia is advisable. The mastoid region is surgically cleansed; the auricle is pulled forward and a free incision is carried down to the bone, in a curved direction downwards over the mastoid process. Originally Wilde made a vertical incision; but it is better, if possible, that the incision should be the same as would be made in performing the mastoid operation, which indeed will probably have to be carried out afterwards. After the hÆmorrhage has ceased and the purulent contents of the abscess, if present, have drained away, fomentations should be applied and changed frequently during the first twenty-four hours. After this a simple dry dressing is sufficient.

Results. Except in the case of tiny infants, this procedure is seldom successful in curing the condition, and must be considered as only a temporary measure.

SCHWARTZE’S OPERATION

(Opening of the mastoid process and antrum)

Indications. (a) In acute middle-ear suppuration. (i) If, in spite of free drainage, earache, pyrexia, and tenderness over the body of the mastoid do not abate within three days. This is all the more urgent if the condition is the result of scarlet fever or influenza, as in these cases the disease may spread with extreme rapidity.

(ii) If there be an obvious abscess over the mastoid process; except in infants, in whom Wilde’s incision may be attempted as a tentative measure, although it is not recommended.

(iii) If there be symptoms of meningeal irritation.

(iv) If a profuse otorrhoea has continued for over four weeks and is accompanied by sagging downwards of the upper posterior wall of the external meatus, a definite sign that the antrum is involved.

(v) If a profuse otorrhoea has continued for over eight weeks, with no sign of abatement, even although the temperature may be normal and although there may be no symptoms of inflammation of the mastoid process. The continuance of the otorrhoea is presumably due to accumulation of pus in a large antral cavity. The object of the operation is to permit of free drainage and to prevent involvement of the mastoid process itself. The question of operation, however, must be considered very carefully. There is no doubt that in many cases conservative measures may effect a cure even although the suppuration has already existed for many months.

(b) In chronic middle-ear suppuration. Although the complete mastoid operation is usually indicated, yet the simple opening of the mastoid antrum may be advised under the following conditions, provided there are no symptoms of inflammation of the mastoid process nor signs of disease of the bony walls of the tympanic cavity:—

(i) If the perforation, however large, be surrounded by a rim of tympanic membrane (showing that there is no disease of its bony margins), and if the malleus be not adherent to the inner wall of the tympanic cavity.

(ii) If the hearing be good, that is, if speech is heard farther off than 12 feet, especially if the other ear (from whatever cause) be quite deaf.

Politzer, among others, still maintains that there is frequently no communication between the affected mastoid cells and the antrum if the mastoid abscess is the result of acute middle-ear suppuration. For this reason he considers that the antral cavity should only be opened if there be definite evidence of bone disease between the abscess cavity and the antrum, or if symptoms of extra-dural abscess or some intracranial complication be present. It is, however, difficult to believe that some communication, however microscopic, does not always exist between the antrum and the mastoid cells, seeing that the latter originally developed as outgrowths from the antrum itself, and must have become infected by direct extension from it. At the same time there is no doubt that complete recovery takes place in a certain number of cases in which the antrum has not been opened.

In my opinion, however, it is always wiser in such cases to open the antrum. Politzer considers that if this be done, healing does not take place so rapidly as in those cases in which the antrum has not been opened. On the other hand, if the antrum be not opened, the main object of the operation, that is, free drainage of the contents of the aural cavity, is not attained.

Operation. Preparation of the patient. The head should be shaved for a space of 2 inches around the mastoid region, twenty-four hours before the operation if possible. In women the hair in front of the ear, instead of being shaved off, should be combed forward and plastered down with carbolic soap. By doing this the hair can be arranged so as to cover the bald area during convalescence, a matter of great satisfaction to the patient.

The area of the operation and surrounding parts should be thoroughly washed with ethereal soap solution and afterwards protected with a compress of 1 in 2,000 solution of biniodide of mercury. After the patient has been anÆsthetized, the cleansing process should be repeated, and the auditory canal syringed out with the lotion. The head is then covered with a sterilized towel drawn tightly over the ear and scalp, a portion of the towel being afterwards cut away so as to expose only the field of operation. The patient should be in the recumbent position, the head resting on some hard substance, such as a partially-filled sand-bag, and turned over to the opposite side, so that the affected ear is uppermost.

In addition to the ordinary instruments, those specially required for this operation are a well-balanced mallet and several gouges and chisels of varying size, one or two sharp spoons, a seeker, and a malleable blunt-pointed silver probe. They should be sterilized in the ordinary manner.

The incision. The surgeon stands at the side to be operated upon, facing the patient’s head. The auricle is pulled forward. An incision is made through the skin, beginning just above the pinna, and is carried downwards in a curved direction towards the tip of the mastoid process, lying about half an inch behind the insertion of the auricle (Fig. 216). Before making the incision, the tip of the mastoid process should be determined. Care must be taken not to let the knife slip at the end of the incision and so incise the neck tissues. The line of incision should correspond to what will afterwards be the middle of the wound cavity in the bone. If the incision be made too far forwards or too far backwards, one of the edges of the skin incision may afterwards tend to overlap the opening in the bone and in this way hinder the dressing and perhaps lead to the formation of a sinus. If there be much thickening of the soft tissues and periosteum, it may be necessary to make the incision longer than usual in order to expose the field of operation sufficiently.

In the upper angle of the incision the temporal fascia and the underlying temporal muscle will be exposed. Except in very muscular subjects, in whom the muscle comes low down into the wound and has to be cut through, it is better to push the lower border of the muscle upwards by means of a periosteal elevator. The incision is now carried right down to the bone throughout its length.

If there be an abscess over the mastoid process, its purulent contents should be allowed to drain away, the abscess cavity being then irrigated with a weak solution of biniodide of mercury (see p. 389).

Exposure of the field of operation. The periosteum and overlying soft tissues are then reflected forwards and backwards with a rugine, until the following points are brought into view: namely, the upper posterior margin of the bony meatus (taking care not to separate the fibrous from the bony portion of the meatus) and Henle’s spine in front, the zygomatic ridge above, and the fibres of the sterno-mastoid muscle below (Fig. 217). The tip of the mastoid process should just be seen. To do this it may be necessary to cut away some of the fibres of the sterno-mastoid muscle.

If the surgeon has two assistants, the duty of one of them is to hold apart the edges of the wound by means of retractors, whilst the other is employed in keeping the wound dry. If there be only one assistant, the edges of the wound may be held apart by metal retractors.

Careful examination of the field of operation should now be made. There may be no external signs of disease. As a rule, however, as a result of the inflammatory process having already extended to the surface, the periosteum is found to be much thickened, with extreme vascularity of the underlying bone, or there may be a subperiosteal mastoid abscess of varying size.

Excepting in infants, in whom pus may escape through the squamo-mastoid suture, a subperiosteal abscess is always secondary to a fistula in the bone, which is usually situated over the body of the mastoid process just behind the suprameatal triangle. It may, however, occupy some other position.

In the case of Bezold’s mastoid abscess (see p. 389), although no fistula may be seen on the surface of the bone, pus may be found to well up from beneath the mastoid process on cutting through the fibres of the sterno-mastoid muscle. In other cases there may be actual necrosis of the bone, as a rule involving the lower margin of the squamous portion of the temporal bone (see p. 390).

The method of opening the antrum in a straightforward case will first be described.

Opening the antrum. The approximate surface marking of the antrum is the suprameatal triangle and the region just behind it, which, however, as has been mentioned, is an uncertain guide. It is wiser, therefore, in all cases of operation on the mastoid process to assume that the case is one in which the lateral sinus extends far forward and is superficial, and that the middle intracranial fossa is low lying.

The area of bone to be removed depends on the age of the patient; in the adult it is about half an inch square, having as its boundaries the zygomatic ridge above and Henle’s spine in front.

The bone should be removed by short decided taps of the mallet on the gouge or chisel, held in contact with the bone in a sloping direction (Fig. 217). This precaution is specially indicated whilst in the act of removing the bone from above downwards and from behind forwards, in order to prevent injury to the middle fossa, which may be low lying, or the lateral sinus, which may project abnormally far forward (Fig. 218).

To permit of better control over the instrument, the hand holding it may rest lightly against the patient’s head, which is now covered with a sterilized towel. This control should always be sufficient to prevent the chisel or gouge being driven unexpectedly too far inwards, an accident which may easily happen if, by chance, there is a sudden diminished resistance to the stroke owing to unexpected softening of the bone or the inadvertent exposure of the dura mater. It is this accidental slipping of the instrument which is often responsible for injury to the lateral sinus or the facial nerve. With regard to choice of instruments, I prefer the gouge, as it is safer than the chisel, owing to it having rounded edges.

On removal of the superficial part of the cortex, the mastoid process may be found to be sclerosed, or to consist of small or large cells filled with granulations or purulent secretion.

(a) If the bone be sclerosed. The operation may be extremely difficult, as the antrum is frequently of small size and very deeply placed. As the tympanic cavity must not be interfered with, it is not permissible to insert the seeker along the auditory canal into the attic in order to determine the position of the aditus. The only guides, therefore, are the anatomical landmarks.

The best method is to chisel away the bone close to and parallel to the upper posterior margin of the external meatus. In chiselling along the upper wall of the opening, the gouge, instead of being directed downwards, as was the case in removal of the outer portion of the cortex, is now directed inwards and at the same time slightly upwards and forwards. In enlarging the lower part of the opening, the bone is chiselled away obliquely inwards and upwards. The strokes of the gouge are made alternately from above and below, so that gradually a funnel-shaped opening is formed, having its point directed towards the aditus.

Anteriorly, the bone is removed as close to the posterior wall of the auditory canal as possible, including the suprameatal spine. Above, the line of chiselling must not extend beyond the zygomatic ridge, whilst below sufficient bone should be removed towards the tip of the mastoid process to permit of inspection of the deeper parts of the wound.

From time to time the operator makes use of the seeker (Fig. 219). This is a blunt-pointed probe whose tip is bent at right angles to its shaft. With it any opening is probed carefully to see whether it is merely a mastoid cell, or dura mater covering the outer wall of the lateral sinus, or the middle cranial fossa, or if indeed it is the antrum itself. The chief mistake is to work too low down. If the antrum be small it may be missed, and the bone may be chiselled away too deeply in endeavouring to discover it and the facial nerve or the external semicircular canal injured. It is wiser, therefore, to work high even if the dura mater of the middle fossa is exposed by doing so. This should not lead to any harmful result provided the dura mater is not injured.

As soon as the antrum is reached, pus will be seen to ooze through the opening made, especially if it is under tension. The probe or seeker can now be passed into a cavity of varying size. The antrum is recognized by its smooth surface, which has quite a different appearance to that of the mastoid cells.

(b) If the mastoid be not sclerosed. The pathological condition found on removal of the superficial cortical layer depends on the anatomical structure and on the extent and virulence of the inflammatory process. Only a few cells may be involved, or on the other hand the whole mastoid process, if it be of the pneumatic type, may be converted into a mere shell of bone, forming a large cavity filled with masses of septic granulation tissue, carious bone, and pus. Sometimes, indeed, owing to the tegmen tympani or bony wall of the sigmoid sinus being already destroyed, the dura mater above or the lateral sinus posteriorly may be found already exposed within the cavity. If this is the case the pus may pulsate if present in large quantity. Any patches of soft carious bone or granulation tissue should be removed with the curette.

If the disease be limited to a few superficial mastoid cells, it is sufficient, according to those who do not always explore the antrum, to expose and curette the cavity freely and to do nothing further. This, however, should only be done if the bone surrounding the abscess cavity is hard and apparently normal, and if there is no tract of granulations leading from it in any direction. If an opening be found leading directly into the antrum, it should be enlarged with the curette or gouge. The extent of the antrum is next defined with the seeker, any overlapping ledges of bone being removed by the gouge until the whole of its inner surface is exposed.

The region of the aditus is now inspected under good illumination, using a head-light if necessary. It is recognized as a small opening at the anterior inner part of the antrum, on the floor of which may be seen the posterior border of the external semicircular canal, standing out as a whitish rounded eminence. Bone may be removed from its upper inner margins, but the lower portion should not be interfered with for fear of injuring or displacing the incus. To confirm the opening into the aditus, a blunt-pointed curved probe may be passed for a short distance through the aditus into the attic (Fig. 220).

With the curette all granulations should be removed.

Treatment of the mastoid process. The question now arises as to how much bone to remove. This depends on the condition found; the chief point is to make certain of removing all the infected cells.

In the case of marked sclerosis, the opening need not be large because, if the bone between the cortex and the antrum be solid, it is hardly probable that infection can spread through it to any outlying cells in the tip of the mastoid or elsewhere.

In the diploic and pneumatic varieties, the seeker must be used constantly in order to discover any outlying cells, which are then opened freely. If this be done systematically, infected cells may be found some distance away from the antrum itself, although an area of apparently healthy bone lies between them and the antrum. It must not be forgotten that cells may extend posteriorly as far as the occipital bone, or anteriorly along the zygomatic process, or even into the upper posterior part of the auditory canal itself (see p. 374). If such infected cells be not discovered, healing will be prevented.

However small or large the opening may be, all rough corners must be removed, so that at the end of the operation a smooth funnel-shaped cavity exists. To obtain this a burr may be used, worked either by the electric motor or, if a portable one, by an assistant. The burrs are of various sizes and of the cross-cut variety recommended by Ballance. Some operators perform the operation by burring throughout. Personally, during the earlier stages of the operation, I prefer to use the gouge and mallet. If the operator has not had much experience in the use of the burr there is always a slight risk, if it be not kept sufficiently under control, and especially if too great pressure be used, of it being driven through the dura mater above or into the lateral sinus posteriorly, or of it injuring the contents of the tympanic cavity. As a means of finishing the operation no instrument could be better. In private practice, however, few surgeons keep one. For this reason it is advisable to become accustomed to the chisel and gouge.

Removal of part of the posterior wall of the auditory canal. This may be necessary if the anterior wall of the antrum and mastoid process be affected. The fibrous portion of the auditory canal is partially separated from the bony portion and held forward by means of a retractor. The upper posterior portion of the bony meatus can now be removed either by means of punch-forceps or by the chisel, to what extent does not matter so long as its innermost portion, ‘the bridge,’ is not interfered with, that is, so long as the tympanic cavity and aditus are not encroached upon.

Exposure of the dura mater and lateral sinus. This may have already occurred before the operation, as a result of extension of the bone disease, or it may be necessary to do so during the course of the operation. Owing to the fact that an extra-dural abscess is a frequent complication of acute inflammation of the mastoid process, Victor Horsley and KÖrner advocate the exposure of the dura mater and the lateral sinus in every case, especially if a tract of carious bone leads in their direction. No harm is done in exposing these structures, and it precludes missing an extra-dural abscess.

It is better to expose the dura mater than to leave it covered with infected bone and septic granulations.

Final step of the operation. In order to make certain that a free opening exists between the antrum and the tympanic cavity, some warm boric lotion should be syringed through the opening of the aditus. A small syringe is used, having a fine piece of india-rubber tubing fixed on to its point. The end of the tubing is pushed into the entrance of the aditus. The fluid is then syringed through and should emerge from the external meatus. This is also beneficial in order to cleanse the tympanic cavity of its purulent secretion. To expel all the fluid from the middle ear the syringe is emptied and the piston withdrawn to its full extent. Its point is again placed within the entrance of the aditus and the piston pressed home, so that air is forced through and so drives out any remaining fluid from the tympanic cavity into the external meatus, which in its turn should be carefully dried. If there be no perforation, or if it be very small, the membrane should be freely incised before fluid is syringed through the aditus.

Immediate treatment of the wound cavity. The wound cavity is lightly packed with sterilized ribbon gauze, half an inch in width. Care must be taken to introduce the gauze right down to the aditus and to pack the cavity evenly.

The wound should be left open for a few days until the acute inflammation of the soft tissues has subsided, after which the upper and lower angles of the wound can be partially closed by sutures. A strip of gauze is also inserted into the auditory canal and a light dressing of plain sterilized gauze and a pad of cotton-wool covers the ear and surrounding parts. The bandage should be passed round the head and not beneath the chin, as the latter method is often a source of great discomfort to the patient during the stage of vomiting following the anÆsthetic.

Blake of America has suggested that the wound should be allowed to fill with blood-clot on the supposition that the subsequent organization of the clot will result in a rapid closure of the wound. This method cannot be considered seriously owing to the impossibility of keeping the wound sterile.

After-treatment. There is seldom any shock, but there may be considerable pain during the next twenty-four hours.

If there has been no subperiosteal abscess, the dressing need not be removed for forty-eight hours. If an abscess has been present the dry dressing should be removed after twenty-four hours, and if there is much oedema and inflammation of the surrounding region, a compress of wet boric lint, kept in position by a few turns of a bandage, should be substituted, and changed every four hours.

Drainage tubes should be shortened and removed as soon as possible. The gauze within the wound cavity should be changed every second day, or daily if there be much secretion. If there be much discharge and the condition be very septic, an ear-bath of hydrogen peroxide may be given at each dressing and the cavity syringed out with a weak solution of biniodide of mercury; otherwise it is sufficient to use boric acid lotion.

If the operation has been successful, the purulent discharge from the tympanic cavity rapidly diminishes, frequently ceasing before the third day. The auditory canal is then firmly packed with gauze, especially in its outer part, in order to prevent stenosis of its lumen, which is liable to occur if the posterior fibrous portion of the canal has been separated from the bony meatus during the operation. Granulations very quickly block the aditus and so separate the antrum and mastoid cavity from the tympanic cavity. The wound can now be treated as an ordinary deep surgical wound, care being taken that it is packed from the bottom at each dressing.

If all the diseased bone has been removed, smooth healthy granulations will cover the wound. The continuance of pus from any spot, or the local growth of exuberant granulations, suggest the presence of an infected cell or a fragment of carious bone. Under cocaine anÆsthesia, the part should be inspected carefully, and, if necessary, curetted freely. In other cases the local application of chromic or trichloracetic acid is sufficient.

After the second week the wound becomes shallower, actual healing of the wound depending on the size of the cavity.

Unless a very large amount of bone had to be removed, the resulting deformity is not great and usually only consists of slight sinking in of the skin. In some cases the final result is only a fine scar, which can generally be concealed by the hair.

The difficulties and dangers of the operation are considered in the next chapter (see p. 412).

Results. 1. If the operation has been successful (and this is usually the case), pyrexia and pain rapidly disappear, the patient experiencing remarkable relief from the head symptoms, so that within twenty-four hours he feels almost well. Healing of the wound is usually complete within six weeks, and before this date the hearing power will probably have been restored to normal.

2. The operation may not have been successful and the following unfavourable symptoms may occur:—

(a) The pyrexia may continue irregularly for a few days. If there be no other symptoms, this is probably due to septic absorption from the wound and need not cause very great alarm. If accompanied by pain, it may either mean that all the infected mastoid cells have not been opened, or suggest the onset of osteomyelitis of the temporal bone. If, in addition, such symptoms as rigors, delirium, optic neuritis, headaches, or vomiting occur, they indicate some intracranial complication.

In cases of doubt it is wiser to explore the wound under a general anÆsthetic and then to determine what operation will be necessary.

(b) The general condition of the patient may be excellent, but otorrhoea or a fistula over the mastoid process may persist. Continuance of otorrhoea, in spite of healing of the wound posteriorly, means that although the disease involving the mastoid process has been eradicated, yet the walls of the tympanic cavity are themselves involved. This will probably necessitate the subsequent performance of the complete mastoid operation.

On the other hand, the suppuration may cease from the middle ear with complete recovery of hearing, and yet a fistula of the mastoid may remain. This means that all the diseased bone has not been removed. This should now be done.

TREATMENT OF SPECIAL CONDITIONS

In an infant. In an infant under two years of age the incision should be somewhat higher than usual. In making it, too much pressure should not be used, as the bone is frequently thin at this age, and if carious it may be so soft that the knife may possibly enter the intracranial cavity. In exposing the area of operation, it must be remembered that the posterior root of the zygoma and the antrum lie at a much higher level than in the adult. The opening into the antrum, therefore, is made almost above rather than behind the margin of the auditory canal. In these cases a fistula is usually present, and the bone is so soft that it can generally be removed by means of a sharp spoon or curette. At the same time, however, the aditus should be exposed and the opening made funnel-shaped in order to allow of proper dressing.

Subperiosteal abscess. The treatment depends on the extent of the abscess. If it be small, the lining membrane may be dissected away, the wound being afterwards treated in the ordinary manner. If the abscess cavity extends upwards towards the parietal region, or forwards along the temporal fossa, then drainage tubes should be inserted, their ends being brought out into the mastoid wound. It is rarely necessary to make counter-incisions. The completion of the operation is seldom difficult, as the fistula actually leads into the antrum. If the fistula be a large one and the bone is carious a sharp spoon may be used; otherwise a gouge is necessary.

Bezold’s mastoid abscess. If the lower portion of the mastoid process be composed of large cells, the abscess within the mastoid may break through the bone at its inner surface in the region of the digastric fossa. In consequence of this the pus may infiltrate the neck tissues beneath the fascia of the sterno-mastoid muscle and form a large abscess recognized clinically as a hard and painful swelling situated below the mastoid process instead of over it. This condition was first described by Bezold.

After exposing the antrum in the ordinary way, the tip of the mastoid process is opened freely. It is usually found to contain large cells filled with pus. Any granulation tissue is curetted away and the cavity dried. The inner surface of the bone is then inspected carefully in order to find the opening, which usually leads into the digastric fossa. The margins of the fistula should be curetted freely and the opening enlarged, if necessary. If the deep-lying cervical abscess be large, the finger may be passed into the abscess cavity behind the mastoid process, between it and the cut fibres of the sterno-mastoid muscle. In this way the limits of the cavity can be made out, and any septa forming pockets within it can be broken down. A counter-incision should be made through the tissues of the neck at the lower limit of the abscess. The opening should be sufficiently large to permit the insertion of a large drainage tube into the cavity. If the abscess be small it may not be necessary to make a counter-opening, but merely to insert a drainage tube into it, passing it from above downwards along the passage made by the finger.

Necrosis. In children necrosis of the temporal bone is not uncommon, especially if the middle-ear suppuration occurs in the course of a specific fever or is the result of tuberculous infection.

The part usually affected is the lower margin of the squamous portion of the temporal bone and the tympanic ring. Sometimes, however, the necrosis is very extensive, involving a large area of the petrous bone, including the labyrinth. These cases are always grave, and if a fatal result occurs it is usually in consequence of meningitis.

In adults necrosis is rare excepting as a localized patch usually situated superficially in the cortex of the mastoid process. Partial necrosis of the labyrinth, more especially of the vestibule and the portions of the semicircular canals, is also met with occasionally. When the necrosed area is superficial, such as the squamous portion of the temporal bone or the cortex of the mastoid process, it should be removed. If, however, it be situated more deeply, forcible removal should not be attempted until the sequestrum becomes loose, the wound cavity being meanwhile kept as aseptic as possible.

Osteomyelitis. In children, as the result of acute inflammation of the mastoid process, the bone may be found riddled with small points of pus, sometimes termed osteomyelitis. As a result of free opening of the mastoid cavity recovery, as a rule, takes place in the ordinary manner.

Distinct from this is another condition in which thrombosis of the diploic veins occurs. It is, fortunately, a rare complication of mastoid disease. It may occur before operation or be the result of infection of the bone as a result of operation. The infection tends to spread in every direction, more especially upwards along the parietal region and towards the occiput. With this, localized areas of necrosis or abscesses may occur, giving rise to painful swellings on the head, and usually are accompanied by cellulitis of the scalp, pyrexia, and intense headaches.

The only chance of recovery is to expose the affected area freely, and thoroughly remove all the diseased bone. To do this it may be necessary to lay bare the dura mater over a considerable area. If, however, the disease be not quickly eradicated, death will eventually occur as a result of extension of the septic infection to the larger veins, or from some other intracranial complication.

CHAPTER VI
THE COMPLETE MASTOID OPERATION

Before considering the question of the radical operation, it is assumed that conservative treatment has been attempted and has failed, and that the middle-ear suppuration has existed for a considerable period.

Indications. (i) As a prophylactic measure. If there be merely a perforation of the tympanic membrane and no evidence of disease of the ossicles nor the walls of the tympanic cavity, the probability is that the continuance of the suppuration is due to an affection of the mucous membrane rather than of the underlying bone; for example, to a chronic empyema of a large antrum cavity which, owing to its anatomical structure, will not drain freely.

In such cases the complete mastoid operation is only indicated if the deafness is extreme, the bone conduction diminished, and the high tuning-forks not well heard, or if the ossicles are bound down by adhesions to the inner wall of the tympanic cavity, as it is then obvious that the hearing power cannot be restored completely.

It must, however, be remembered that in many cases a slight discharge may exist for years without giving rise to any complications. If the patient be made aware of the slight danger which exists in every case of middle-ear suppuration, and be in a position to obtain medical attention if retention of pus occurs, then operative measures may be deferred indefinitely. If, on the other hand, the patient intends going to some remote country where medical attendance is impossible, then it is probably wiser to submit to the complete operation rather than risk future trouble.

(ii) If there be recurrent attacks of giddiness, nausea, or headaches radiating up the affected side which are not arrested by the ordinary methods of treatment. These symptoms of retention of pus within the antrum and mastoid process should be considered as danger signals. In this case also it is assumed that the hearing cannot be restored, and in consequence there is no object in performing Schwartze’s operation.

(iii) If there be recurrence of polypi and granulations within the tympanic cavity in spite of curetting, especially if the operation of ossiculectomy has already been performed.

(iv) If there be symptoms of retention of pus due to want of free drainage in the case of stenosis of the external meatus, whether due to fibrous contraction of its soft parts, or from the presence of exostoses.

(v) If cholesteatomatous formation be present. Even if there be no symptoms necessitating immediate interference, operation is usually indicated owing to the fact that cholesteatoma is the commonest predisposing cause of intracranial suppuration and septic thrombosis of the lateral sinus.

(vi) If there be a fistula of the bony wall of the mastoid process, whether it extends anteriorly into the auditory canal or externally through the skin over the region of the mastoid process. It must not be forgotten, however, that simple opening of the antrum and mastoid cells will be quite sufficient if the condition is the result of a recent and acute inflammation of the mastoid process.

(vii) If there be facial paralysis occurring in the course of a chronic middle-ear suppuration. This may mean either that there is bone disease involving the facial canal, or that the inflammatory process has spread through the Fallopian canal towards the inner ear. In either case operation is indicated.

(viii) As a preliminary step in intracranial suppurative lesions of otitic origin.

(ix) In tuberculosis of the middle ear. If the patient’s general condition permits of it, and if the pulmonary disease be slight or arrested, the complete operation should always be done. The difficulty is to remove all the diseased bone. If this can be done the wound will heal quite well.

(x) In acute inflammation of the mastoid process occurring in the course of chronic middle-ear suppuration, the complete mastoid operation should be performed, as in these cases the attic, aditus, and antrum are always involved.

(xi) Amongst the rarer conditions for which the complete operation may be necessary are removal of a foreign body which has been pushed inadvertently into the region of the attic and aditus and cannot otherwise be removed; and actinomycosis of the temporal bone.

METHODS OF OPERATION

The actual method of carrying out this operation varies. For those who have not had great experience the best method is first to open the antrum, as in Schwartze’s operation, and then to remove the ‘bridge’ of bone between it and the tympanic cavity (KÜster-Bergmann operation, sometimes called the Schwartze-Stacke operation). Instead of doing this, the upper posterior part of the auditory canal may be chiselled away simultaneously during the act of exposing the antrum (Wolf’s operation). On the other hand, the mastoid and antrum may be exposed from within outwards by removing the outer attic wall and working backwards (Stacke’s operation).

The KÜster-Bergmann (or Schwartze-Stacke) operation. The preliminary preparation, the position of the patient, and the instruments required are the same as in opening the antrum.

The incision is begun just above the upper insertion of the pinna, and is carried downwards in a curved direction behind the auricle along the margin of the skin and scalp. Some authorities prefer to make the incision close behind or even along the post-auricular fold. In favour of the incision being placed far back is the concealment of the scar by the hair. Also, as it is situated on healthy bone somewhat posterior to the actual wound cavity, it should heal by primary union and with no after-displacement of the auricle. In addition, if it be necessary to expose the lateral sinus, this can usually be done by simple retraction of the soft parts.

The exposure of the field of operation is the same as in the simple opening of the antrum, excepting that the soft tissues should be separated a little further forwards and above the external bony meatus, as in this operation the upper posterior wall has to be removed.

The antrum is opened as already described (see p. 382).

The fibrous portion of the external meatus is separated carefully from the posterior wall of the bony meatus by means of a periosteal elevator, and is pulled forward by a retractor. The external portion of the posterior wall is now removed in a wedge-shaped fashion by alternate strokes of the chisel from above downwards (Fig. 221) and from below upwards. The upper level of the bone to be removed corresponds with the zygomatic ridge. After a small portion has been removed, a pair of forceps is passed into the auditory meatus and its point made to project into the wound posteriorly through the end of the now detached fibrous portion of the auditory canal. With the forceps a piece of gauze is drawn through the auditory meatus in the form of a loop. By its means the auricle and fibrous portion are pulled well forward, thus exposing to view the tympanic cavity. Two openings are now seen: one, the auditory canal and tympanic cavity, in front, and the other, the antrum and mastoid cavity, behind. Between them is the ‘bridge’; that is, the innermost portion of the posterior wall of the auditory canal.

Any granulations present are curetted away gently from the tympanic cavity. The seeker is next passed into the tympanic cavity, and its point directed upwards and backwards into the aditus, so that it rests on the floor of the latter, or its point may be inserted into the aditus through the mastoid wound. Beneath it lies the eminence of the external semicircular canal and the facial nerve. This is a most important landmark. Provided the seeker is kept in this position, all the bone lying superficially to it can be removed without injury to the semicircular canal or facial nerve.

In this connexion may be mentioned Stacke’s probe or ‘protector’ (Fig. 222). Although historically an instrument of importance, I do not make use of it. It is so large and of such sharp outline that, unless used with extreme care, it is itself very liable to injure the facial nerve. For this reason I prefer the seeker, a much finer and more delicate instrument, which will serve the purpose without the same risk (Fig. 219).

The ‘bridge’ is now carefully removed by the gouge or chisel, frequent use being made of the seeker meanwhile. As the roof of the antrum, aditus, and attic is a continuous one, the bone to be removed is necessarily at a higher level than the roof of the bony meatus. This is a point which must not be forgotten, as the great fault of the beginner is to remove the bone too low down.

As the aditus is approached, the strokes of the chisel must be very gentle. If too much force be used, the chisel, on breaking through the innermost portion of the ‘bridge’, may injure the deeper-lying parts, more especially the facial nerve.

Some authorities advocate removal of the ‘bridge’ by means of bone forceps. This, however, is not so sure a method as by the chisel or gouge.

After removal of the bridge, the tympanic cavity, antrum, and mastoid will form a continuous cavity. As a rule the outline of the external semicircular canal appears as a well-marked white eminence, and projecting beyond it are the remains of the posterior wall of the auditory canal. In removing this ridge good illumination is essential. The bone is removed in layers with the chisel, beginning at the tip of the mastoid process, and working parallel to the auditory canal and the underlying facial canal. If necessary the seeker may be used as a guide, its point being allowed to rest on the floor of the aditus, superficial to the semicircular canal (Fig. 223).

The amount of bone removed should be such that at the end of the operation the auditory canal is only separated from the main cavity of the mastoid antrum by a slight eminence, the remainder of the posterior wall, which is continuous with that of the external semicircular canal.

Occasionally the facial canal and the stylo-mastoid canal are abnormally superficial. Provided the bone be removed in the manner just described, the facial nerve should not be injured, even though it may be exposed inadvertently. A warning of this occurrence is given by bleeding from the vessels within the canal (see p. 374).

If the malleus and incus be still in situ, they can now be seen and can usually be removed by the curette. No force must be used. Removal of the incus is a matter of no difficulty. In the case of the malleus there may be some resistance owing to the attachment of the tendon of the tensor tympani muscle. If so, the malleus should be grasped by a fine pair of forceps and the tendon severed by means of Schwartze’s tenotomy knife.

The overhanging edge of the outer wall of the attic can now be felt by means of the seeker. It is best removed by gentle taps of the chisel or small gouge. Especial care must be taken not to drive the gouge too far inwards. If this be done inadvertently, the transverse portion of the facial nerve passing along the inner wall of the tympanic cavity may be injured. As a safeguard some surgeons use an attic punch-forceps or a burr, others a Stacke’s protector which should be inserted into the attic before chiselling away its outer wall.

After the outer attic wall has been removed, the roof of the auditory canal and the attic should be continuous. This is verified by inserting the seeker, with its point turned upwards, within the attic, and then withdrawing it; no ridge of bone should now prevent its withdrawal.

Granulations or the epithelial lining of cholesteatomata should be removed from the recesses of the tympanic cavity with a small curette. Care must be taken not to injure the surface of the promontory, or the region of the fenestra ovalis and fenestra rotunda. It is especially important to curette away the mucous membrane from the orifice of the Eustachian tube in order that scar tissue may obliterate its lumen and so prevent reinfection of the middle ear from the naso-pharynx. For this purpose a narrow curette is necessary (Fig. 224).

Removal of the innermost portion of the floor of the auditory canal is not always necessary. Sometimes, however, the ‘hypotympanum’ is well marked, and in order to ensure a good result it is wiser to remove this projecting piece of bone. If the ridge of bone be removed piecemeal, and if the gouge or chisel be kept parallel to the floor of the canal, there should be no danger of wounding the bulb of the jugular vein. Cases, however, have been recorded in which this has occurred.

The final step is to see that no pockets nor overhanging ledges or ridges of bone remain, and that all the diseased area has been removed. The cavity, although irregular in outline, should be a continuous one with a smooth surface (Fig. 225).

Wolf’s operation. This slight modification of the KÜster-Bergmann operation requires merely a note of description. The position of the patient and the preliminary steps of the operation are the same as in the former operation.

In this operation, instead of first exposing the antrum cavity and afterwards removing the posterior wall of the external meatus, this procedure is performed in one step.

The chisel or gouge is first brought into contact with the bone just behind the upper posterior margin of the auditory canal. The bone is removed in layers by chiselling it away in a forward direction and in such a manner that each stroke of the chisel is carried directly into the auditory canal (Fig. 226). With each successive stroke, begun a little more posterior and inferior to the one preceding it, more bone is removed until at length the antrum is exposed. There should be no risk of injuring the external semicircular canal nor the facial nerve, owing to the fact that the outer wall of the antrum lies superficial to the tympanic cavity and aditus.

After the antrum has been exposed, the technique of the operation is the same as that already described in the Schwartze and KÜster-Bergmann operation.

Advantages. 1. If the surgeon be experienced it saves much time, as the preliminary steps of the operation can be carried out very rapidly.

2. If the mastoid be sclerosed and there are no landmarks, the antrum, however small, is bound to be reached by making use of this method, by keeping high up, and, if necessary, exposing the dura mater. To verify the depth to which the bone may be removed and also the position of the antrum, the seeker should be inserted occasionally through the tympanic cavity into the aditus.

Disadvantages. If the surgeon be not experienced, it is not so safe a method as that of first exposing the antrum.

Stacke’s operation. After exposure of the field of operation, as in the KÜster-Bergmann operation, the fibrous portion of the auditory canal is separated posteriorly from the bony portion.

Any granulations, together with the malleus and incus, are removed from the tympanic cavity (see p. 353). Under a good illumination, using a head-lamp if necessary, the surgeon passes a seeker along the auditory canal, its point being made to project into the attic in order to define its limits and that of the aditus. The innermost portion of the upper posterior wall of the auditory canal, that is, the outer wall of the attic, is now removed piecemeal by means of a small gouge (Fig. 227). By working backwards the aditus is approached, the bone being removed carefully in small fragments. The seeker is inserted repeatedly into the entrance of the aditus so as to rest on the external semicircular canal, in order that the position of the latter and the underlying facial nerve may be kept constantly in mind. More bone above and external to this point is removed in small fragments, until at length the upper and innermost portion of the antral wall is removed and its cavity thus exposed. The cavity is gradually enlarged by removing still more bone in a backward and outward direction, until finally it resembles that left after the complete operation. Stacke originally devised this method in those cases in which he considered that the disease was limited to the ossicles, the walls of the attic, aditus, and innermost portion of the antrum. It was, indeed, merely a more radical method of performing ossiculectomy.

Advantages. Although this operation has practically been abandoned as a method of performing ossiculectomy, yet under the following conditions it may be adopted during the performance of the complete operation:—

1. If the mastoid be very sclerosed and if the antrum cannot be exposed, although the bone has been removed to a depth corresponding to its usual position.

2. If there be difficulty in exposing the antrum in the performance of the radical operation owing to the lateral sinus projecting far forwards and the middle intracranial fossa overlapping it externally.

Disadvantages. The chief disadvantage is that it is more difficult and tedious to begin the operation within the depth of the wound, and if the meatus is very deep and narrow it may be almost impossible to carry out.

Preservation of the ossicles and tympanic membrane after performing the complete mastoid operation.

This method of operation is well known and has been performed for some years, especially by Jansen of Berlin, and in America.

The only indication for this modification of the complete mastoid operation is disease involving the antrum and mastoid process so extensively as to require complete removal of the posterior wall of the auditory canal, without there being any coexisting bone disease of the walls of the attic or of the ossicles.

As the complete mastoid operation is only performed for some condition due to chronic middle-ear suppuration, it is difficult to imagine that the ossicles and attic region could remain unaffected when the extent of the disease necessitates the complete operation.

In my opinion, if it be necessary to remove the ‘bridge’ it is also necessary to remove the outer wall of the attic and with this the malleus and incus. If, on the other hand, there be no bone disease of the attic region or of the ossicles, Schwartze’s operation, or some modification of it, should be sufficient. The majority of aurists agree that, excepting in those cases in which the continuance of the suppuration is due to an empyema of the antral cavity, the ossicles are almost invariably carious to a greater or lesser extent in chronic middle-ear suppuration. This view is supported by Grunert’s researches (Archiv fÜr Ohrenheilkunde, Band 40), who found that the ossicles were only normal in five cases in a series of 113 cases in which the complete operation had been performed.

Although removal of the ‘bridge’ may eradicate the disease within the mastoid process and antrum, yet, if the ossicles are left, post-suppurative adhesions will almost certainly afterwards bind them down and so cause a greater deafness than if they had been removed originally. Still, a few isolated cases have been reported in which hearing to the extent of 20 feet or more has been obtained as the result of this operation. The same results, however, frequently occur after the performance of the complete operation with removal of the malleus and incus. Until we have a large and consecutive series, recording the results of this particular operation in detail, together with information regarding the duration of the symptoms, the previous treatment, and the condition of the ear before operation, it is impossible to judge the value of this method.

THE FORMATION OF POST-MEATAL SKIN FLAPS

This is done for two reasons: firstly, to prevent stenosis of the auditory canal; and secondly, to aid the growth of the epithelium over the wound surface, so that the latter will heal as rapidly as possible.

These flaps may be formed in several different ways. The following is the technique I adopt: A long, narrow, curved bistoury is passed down the auditory meatus so that it projects through the detached end of the fibrous portion, its point being directed backwards. The auricle is held well forward and the fibrous portion of the meatus cut through posteriorly, from within outwards, for a short distance (Fig. 228). The edge of the bistoury is then directed in a slanting direction upwards and outwards, and the incision continued as far as the cartilaginous portion of the meatus, care being taken not to cut into the concha. The bistoury is then withdrawn and reinserted at the point at which it was first made to turn upwards. It is now directed downwards and outwards and, in a similar manner, the incision is made in a slanting direction towards the inferior margin of the cartilaginous meatus. In carrying out these manipulations care must be taken that the outer portion of the bistoury does not injure the tragus or other portion of the auricle, a mistake which can easily occur. The fibrous portion of the meatus is thus divided by a Y-shaped incision into three small flaps; namely, a posterior or external V-shaped flap, and a superior and an inferior flap (Fig. 229).

The outer flap is fixed to the skin behind the auricle by means of a catgut suture (Fig. 230), and the auricle is then pulled back into its normal position. By inserting the tip of a finger into the meatus, the upper and lower flaps are pressed upwards and downwards against the roof and floor of the mastoid cavity, and can be kept in position afterwards by suturing the flaps to the subcutaneous tissue or by packing the cavity through the meatus with a strip of ribbon gauze.

Amongst other methods the following may be mentioned:—

KÖrner’s method (Fig. 231). Two parallel incisions are made in a longitudinal direction through the fibrous portion of the posterior wall of the meatus and are prolonged outwards as far as the concha. On the auricle being restored to its normal position, this posterior flap is pressed backwards and so covers a large area of the posterior wound surface. The chief objection to it is that, owing to involvement of the concha, there is considerable enlargement of the meatal opening and therefore subsequent disfigurement.

Panse’s method (Fig. 232). A transverse incision is carried through the posterior margin of the meatus, at the junction of the concha and auditory canal posteriorly. With a pair of scissors or knife, the posterior wall of the fibrous portion of the canal is now split by a longitudinal incision. In this way two flaps are formed, a superior and inferior one. They are fixed into position by catgut sutures through the subcutaneous tissues at the upper and lower angles of the wound.

Stacke’s method (Fig. 233). This consists of a large inferior flap, formed by making a longitudinal incision along the posterior upper border of the fibrous portion of the auditory canal and a transverse incision meeting it at right angles, the latter cutting through the fibrous portion of the meatus at its junction with the concha.

In order that these flaps may be thinner and more adaptable, the subcutaneous tissue should be cut away. Of these flaps the Y-shaped one is the most practicable, as it is suitable whether the posterior wound is closed or left open.

KÖrner’s method has the objection that there is subsequent disfigurement owing to the large meatal opening formed by cutting into the concha. It has the advantage, however, that the large posterior flap will cover the posterior surface of the wound cavity to a considerable extent, and also that it will permit a good view of the surface.

Panse’s flap is only of service if the posterior wound is left open and if there is not sufficient tissue left to make a posterior flap owing to previous destruction of the posterior wall of the auditory canal.

Stacke’s method is good if skin-grafting is afterwards employed.

CLOSURE OF THE WOUND

Excepting under the conditions mentioned below, the posterior wound is closed by bringing together the edges of the skin incision with fine silkworm-gut sutures (Fig. 230). Before this is done, the wound cavity should be irrigated with a weak solution of biniodide of mercury, dried, and the deeper parts of the wound plugged with a strip of gauze inserted through the external meatus. This will not only arrest the hÆmorrhage and keep the inner part of the wound dry, but at the same time will keep the skin flaps in position. After the wound has been closed, firm pressure should be applied in front and behind the ear to press out any blood from the cavity.

As a final step the gauze which has been inserted into the meatus is removed, and the cavity again packed evenly and lightly from the bottom of the wound with a fresh strip. The ear and surrounding parts are protected with a pad of sterilized gauze covered with cotton-wool and kept in position with a bandage.

The posterior wound should be left open under the following circumstances:—

1. If there be an abscess over the mastoid process. Although it may be possible to excise the whole of the lining membrane of the abscess cavity, it is wiser to leave the wound open for the first few days. The innermost portion of the wound cavity is packed through the external meatus, only the superficial part being packed through the posterior wound incision. As healthy granulations appear, the posterior packing is diminished, so that the edges of the incision gradually come together. If necessary, the edges of the wound can also be freshened and brought together by silkworm-gut sutures under cocaine anÆsthesia.

2. If there be extensive disease of the bone, especially if the dura mater and lateral sinus are covered with septic granulations.

3. If there be bone disease of the anterior and inferior parts of the tympanic cavity. The after-treatment of packing or the curetting away of granulations can be carried out more easily through the posterior wound than through the external meatus, as it gives a better view of these regions.

4. In young children it is frequently advisable to leave the posterior wound open owing to the difficulty of packing the wound cavity through the small external meatus.

SKIN-GRAFTING AFTER THE MASTOID OPERATION

In order to shorten the duration of healing, a large Thiersch’s skin graft may be transplanted into the wound cavity. If this procedure be adopted it may be carried out in several ways. The skin may be transplanted in one large piece or in several small portions, and it may be introduced into the wound cavity either immediately after the completion of the mastoid operation or from seven to ten days later.

There is considerable diversity of opinion as to whether skin-grafting should be employed or not, and also when it should be done.

This may be partially accounted for by the fact that although, theoretically, the application of skin grafts is easy, yet, practically, the technique is difficult. Those who favour skin-grafting point to the fact that healing of the wound may take place within five weeks, whereas, if grafting be not undertaken, cicatrization of the cavity, even under favourable conditions, can hardly be expected to occur before eight to twelve weeks.

The skin-grafting operation as suggested by Charles Ballance is generally performed as a second stage, some ten or more days after the primary operation. This, from the patient’s point of view, is a serious matter; and the disappointment caused by the grafting not being always successful has induced many to give it up and to be content with what seems to be a more certain, though more prolonged, after-treatment.

More recently, however, it has been shown that in suitable cases skin grafts, if applied at the time of the completion of the primary operation, will take just as well as at a later date. This altogether alters the aspect of the case. If at the end of the primary operation it be certain that all the diseased bone has been removed and the cavity has been rendered aseptic, there can be no objection to the immediate application of skin grafts. If the result be successful, the period of after-treatment is considerably curtailed. If, on the other hand, it be not successful, the patient, beyond having a raw surface on his arm or leg for a few days, is no worse off than if the graft had not been applied.

Skin-grafting, however, cannot be done in every case. Two conditions are necessary for its success: firstly, that all the diseased bone has been removed; and secondly, that the wound cavity is aseptic.

Immediate skin-grafting, therefore, should not be employed if, in addition to the chronic disease, there be acute inflammation of the mastoid process, or of the subcutaneous tissues covering it; nor should it be done if it has been necessary to expose the dura mater over a large area, nor if there be any possibility of some subsequent intracranial complication. In such cases it may be justifiable to do skin-grafting after the acute symptoms have subsided. If, however, the case be progressing satisfactorily, the advisability of submitting the patient to a second operation should be a matter of careful consideration.

Disease of the inner wall of the tympanic cavity, or around the orifice of the Eustachian tube, is also a contra-indication against grafting, as the graft, if applied, will not take over these areas. The author’s opinion with regard to skin-grafting is that, if it can be applied immediately after the completion of the primary operation (and the conditions justifying this are limited), it may be done. If, however, the conditions be such that they will not permit of this, it should not be done at all.

Technique. When the grafting is done at the completion of the mastoid operation. The first step is to see that the mastoid wound cavity is rendered thoroughly aseptic and dry. All bleeding points in the soft tissues are arrested by means of pressure forceps. The mastoid cavity is then filled with hydrogen peroxide lotion, which is afterwards syringed out with a warm saline solution, the cavity being dried with sterilized strips of gauze, and finally packed from the bottom with a fresh strip.

The size of the graft, which is usually taken from the thigh, should be at least 2 inches in width and 4 inches in length. The skin is cleansed by washing it with soap and water, then with ether, and finally with normal saline solution, the part being afterwards dried with a sterilized towel. It does not matter what type of razor is used to remove the graft, so long as it is sharp. The chief point to observe, in order to secure success, is to see that the skin is kept uniformly stretched—the tighter the better. The technique of removal of grafts is described elsewhere (see Vol. I, p. 670). The graft taken from the leg is transferred to a large spatula and smoothed out over its surface. The auricle is now pulled forward, and the gauze strip is removed from the mastoid cavity. The spatula is laid across the surface of the cavity so that it rests on the anterior margin of the wound surface (Fig. 234). With a sharp probe the edge of the graft, which just overlaps the spatula, is held in position at this point, the spatula being gently retracted so as to leave the graft stretched across the surface of the wound cavity. With a ‘stopper’ (Fig. 235), the graft is now pushed inwards towards the tympanic cavity.

A glass pipette (Fig. 236), having a curved beak, is then passed inwards beneath the graft until its point, directed downwards, lies within the tympanic cavity (Fig. 237). Any blood which has accumulated between the bone and the graft is now sucked out, and in doing this the graft becomes closely applied to the bone surface (Fig. 238). After removing the pipette, any part of the graft which is not adherent to the bone is smoothed out over its surface. The tympanic cavity and the innermost portion of the mastoid cavity are then plugged with sterilized pellets of cotton-wool wrapped in gauze and dusted with aristol powder. The outer portion of the cavity is filled up with a strip of gauze, its end being brought out through the external auditory meatus.

The posterior part of the graft, still projecting beyond the posterior margin of the wound, is now turned forwards so as to form a covering over the gauze filling up the wound cavity (Fig. 239). On the auricle being restored to its normal position, this portion of the graft is brought into contact with the subcutaneous tissues of the skin forming the post-aural flap, which now forms the outer wall of the mastoid cavity. The posterior incision is closed with sutures and a dry dressing and bandage are applied to the ear.

If skin-grafting be performed a week or more after the primary operation. The post-aural wound, now healed, has to be reopened. In doing so there may be considerable bleeding, which must be arrested. The mastoid cavity is usually found to be covered with a fine layer of granulations. They are curetted away carefully, special attention being paid to the region of the Eustachian tube and the floor of the tympanic cavity. After removal of the granulations, the bone should appear uniformly smooth though somewhat vascular. If any points of carious bone be found they should be removed freely with the gouge or burr. Considerable time may have to be spent in arresting the oozing from the surface of the bone cavity. This is best done by washing out the cavity with hydrogen peroxide solution and then plugging it tightly for a few moments with adrenalin solution. The gauze is withdrawn in a few moments. If there be still oozing, the pressure will have to be repeated until it ceases. The method of applying the graft is the same as already described.

After-treatment. The outer dressing may be changed every second day, but the wound itself is not interfered with until the eighth day. If asepsis has been obtained, the posterior wound has usually completely healed, so that the stitches can be removed at the first dressing. Owing to the secretion from within the cavity there may be a certain amount of odour, and as a rule some purulent discharge from the meatus. Under good illumination the strip of gauze is gently removed through the meatus and afterwards the small pellets of cotton-wool. In order to make certain that all are removed, a note should be made at the time of transplanting the graft as to how many were inserted in the wound cavity. The ear is now syringed out gently with a weak solution of hydrogen peroxide and afterwards dried by mopping it out with small wicks of cotton-wool.

A speculum is next inserted into the meatus and the cavity thoroughly examined. Any portions of the graft not in absolute contact with the bone or which overlap the skin of the meatus will have died, and can be removed by forceps. Care, however, must be taken not to pull off these portions too forcibly, as in doing so other pieces of the graft may be torn away. The external meatus is then plugged with a tiny piece of gauze and a dry dressing applied. If the graft has not taken and has died, it will be expelled at the first dressing on syringing.

Further treatment consists in syringing and afterwards drying the cavity daily. From day to day the outer layer of the graft will gradually come away piecemeal. At the end of the second week the patient can usually go home and carry out the treatment for himself, but he should be seen by the surgeon at least once a week until complete healing has taken place. If the graft has not taken uniformly over the surface of the bone, small patches of granulations may be seen covering these areas. Under cocaine anÆsthesia these patches should be curetted. If the granulations recur repeatedly, it means that there is some underlying carious bone, and that healing will not take place until the tiny fragment is eventually exfoliated.

Results. Statistics vary. There is no doubt that the results are better according to the experience of the surgeon with regard to grafting. If it be only applied in those cases in which it is certain that all the diseased bone has been eradicated at the primary operation, then the percentage of success with relation to failure is very high. If, however, skin-grafting be adopted as a matter of routine, the ultimate result is probably not so good as in a similar series of cases in which grafting has not been done.

Skin-grafting through the external meatus. This has been advised chiefly in order to avoid a second operation.

The technique of applying the graft is practically the same as that for transplanting a large graft. The same care must be taken to get the interior of the mastoid cavity aseptic and dry. To avoid a general anÆsthetic, the small grafts may be removed from the arm or leg under local anÆsthesia produced by a subcutaneous injection of Schleich’s solution. The graft is transferred from a small spatula to the edge of the meatus and then coaxed into position within the cavity by means of probes. The grafts are kept in position by small pellets of cotton-wool covered with gauze. If successful, the grafting may shorten the duration of the after-treatment. It is not, however, so satisfactory a procedure as applying a large graft directly through the post-aural wound.

In order to keep the grafts in position, Drew has suggested laying the graft on sterilized gold-beater’s skin, and in this way applying it to the interior of the mastoid cavity.

More recently, Stoddart Barr of Glasgow has introduced an ingenious method of getting the grafts into position. The graft is manipulated over the end of a suitably-bent glass tube, having attached to the other end a piece of rubber tubing with a glass mouthpiece or small rubber bag. The graft at the end of the tube is passed through a wide speculum to the inner wall of the tympanum, when, by blowing air through the tube, the graft is spread out over the inner surface, including the tympanic walls, aditus, and antrum.

AFTER-TREATMENT OF THE CASE

If the posterior wound has been closed. Provided the temperature keeps normal and there be no pain and no head symptoms, the first dressing need not take place until the fifth or sixth day. By this time the edges of the skin incision have usually united, so that the stitches can be removed, although occasionally the wound may have to be opened up to permit of drainage on account of septic infection. The withdrawal of the gauze from the auditory canal may cause considerable pain, which, however, can be prevented by continuous irrigation of the ear before and during its removal (see p. 315).

After the gauze has been removed, the ear is mopped out with pledgets of cotton-wool. To relieve the pain a few drops of a sterilized 1% solution of cocaine may be instilled and left within the ear for a few minutes.

Under good illumination, the largest possible speculum is inserted into the meatal orifice. The cocaine solution is mopped out, and the cavity dried, in order that careful inspection of the deeper parts may be made. The chief point is to see that the flaps are in position. There may be slight oozing from the surface of the wound, but as a rule the bone appears almost white, owing to the fact that granulations have not yet begun to form. The wound is then packed gently and evenly with gauze and the ear protected again with an external dressing and bandage.

Until the first dressing has taken place, the patient should be kept in bed. After this, provided the condition be satisfactory, he may be allowed to get up for a few hours every day, the period being gradually increased; by the tenth day or so he is practically well. In an uncomplicated case there is seldom any shock or discomfort after the operation, so that frequently the patient is anxious to be up and about even before the first dressing has been performed. It is wiser, however, to insist on rest for the first few days.

The subsequent dressings should be done every second or third day, depending on the condition found. If the wound cavity be clean, and if there be no odour, it is sufficient to irrigate it with a simple saline or boric lotion. Granulations begin to cover the bone about the tenth day, when there may be some purulent discharge necessitating daily dressings. To keep the parts sweet, an ear-bath of hydrogen peroxide (10 vols. %) may be given, the ear being subsequently irrigated with a 1 in 5,000 solution of biniodide of mercury.

Provided the patient be doing well there should be no temperature, pain, nor headaches. If any of these symptoms occur, or if the patient feels ill, or has attacks of sickness and becomes drowsy, the surgeon should at once be suspicious of some impending intracranial complication.

If the case be progressing favourably and all the diseased area of bone has been completely removed, granulations do not become exuberant, but form a fine smooth layer over the wound surface, the last portion to become covered being the region of the external semicircular canal and the ridge forming the remains of the posterior wall of the bony meatus. Exuberant granulation tissue is significant of underlying bone disease. If patches be observed, a 10% or stronger solution of cocaine should be applied to the part, which should afterwards be curetted. This process may have to be repeated on several occasions until, perhaps, a small spicule of bone is removed, after which granulations usually cease. As a rule the bone is completely covered with granulations by the fifth or sixth week. Meanwhile, owing to the growth of epithelium from the edges of the flaps, the raw surface within the wound cavity gradually becomes smaller, and with this there is diminished secretion.

The gauze packing can usually be discontinued about this period, or considerably earlier, perhaps even by the third week. In its stead an aqueous solution containing 50% of rectified spirit with 10 grains of boric acid to the ounce may be instilled into the wound cavity after it has been cleansed and dried.

Complete cicatrization of the cavity should take place within two or three months, depending on the size of the cavity.

If the posterior wound has been left open, the first dressing should be done on the second or third day.

The subsequent treatment depends on each individual case. If the wound has been left open on account of its septic condition, or owing to the dura mater having been exposed and found covered with granulations, its edges may be brought together by sutures after a period of ten days or so, when the wound cavity looks clean, and the packing carried out through the meatus.

On the other hand, if the wound has been left open on account of bone disease involving the inner wall of the tympanic cavity or region of the Eustachian tube, the packing should be continued through the posterior opening until the patches of carious or necrosed bone heal or are exfoliated. In these cases the granulation tissue tends to become fibrous in character in consequence of the necessary curettings, and eventually to form a thickened pad covering the inner wall.

After complete healing has taken place, the patient, before being dismissed, should be warned to visit the surgeon at least once in three months. Owing to the large cavity being lined with epithelium, desquamation takes place to a greater or lesser extent, so that the wound cavity may gradually become filled with masses of epithelial dÉbris or cerumen. In consequence the cavity may become septic, and on removal of the epithelial dÉbris underlying ulceration may be found. This can usually be cured by aseptic treatment, but if granulations have already occurred, curetting and the application of trichloracetic and chromic acid may be necessary.

DIFFICULTIES AND DANGERS OF THE OPERATION

Anatomical difficulties. The chief difficulties are due to a middle fossa overlapping the antral cavity, a lateral sinus projecting far forwards and lying superficially, and a sclerosed mastoid having no landmarks to indicate the way into the antrum. Unfortunately these conditions are frequently associated.

Formerly it was advised that it was wiser not to proceed further if the antral cavity could not be discovered after chiselling to a depth of three-quarters of an inch. This advice, however, is no longer reliable, as by the combination of the Stacke, Wolf, or KÜster-Bergmann method any anatomical difficulties should certainly be overcome.

An inexperienced operator may mistake a large mastoid cell for the antrum and in this way may get into difficulties. The opening into the antrum, however, can always be identified by passing a bent malleable silver probe in an inward and forward direction into the aditus. If only a large cell has been opened, the probe will show that it is a limited cavity.

HÆmorrhage. In the majority of cases this is more of an inconvenience than a danger, being chiefly due to a general oozing from the soft tissues. It is, however, very necessary that the surgeon should have a clear view of the deeper parts whilst operating. If he works blindly in a pool of blood he courts disaster.

The hÆmorrhage is best prevented by first curetting away any granulation tissue and then packing the cavity firmly with a strip of gauze. If this be not sufficient, it may be again packed with gauze containing adrenalin solution. It will repay the surgeon to have a good assistant to keep the field of operation dry. Troublesome bleeding, coming from a small vessel in the bone, may be arrested by the local application of a small fragment of Horsley’s sterilized wax (see Vol. I, p. 437).

Wound of the lateral sinus. This is a serious matter for two reasons: firstly, it may prevent completion of the operation; and secondly, it may lead to infection of the sinus.

If the sinus has already been exposed before the accident occurs, the surgeon promptly arrests the hÆmorrhage by placing the forefinger of his left hand directly over the wound in its wall and exerts sufficient pressure to completely obliterate the sinus at this point. With his finger kept in this position, the wound cavity is carefully dried, and, if there be sufficient room, a piece of sterilized gauze is then packed between the bone and the outer wall of the sinus, both above and below the site of the injury. If there be not enough room to do this, then the surgeon with his right hand, or the assistant, should punch away more bone by means of bone forceps. After the lumen of the sinus has been obliterated above and below the injured area, the finger may be removed. If the packing has been successful, there will be no bleeding; if there be still slight bleeding, it can be controlled by further pressure. If possible, this method should always be carried out, as it practically excludes any chance of after-infection of the sinus.

If the injury takes place before the sinus has been sufficiently exposed to permit of direct pressure with the finger, then the only thing to do is to press in a small strip of gauze and plug the opening. As to what should be done next is a matter of opinion. Some surgeons are content to leave the gauze in situ. The author prefers to expose the sinus further, as in the former case, and to make certain that it is obliterated above and below the injured area. No doubt, if the injury be slight, the pressure of the strip of gauze covering the puncture will be sufficient to control the hÆmorrhage, and the patency of the sinus may be maintained on healing. At the same time infection of the sinus has been known to take place, although the symptoms of this may not occur for ten days or two weeks after the operation.

If the sinus projects far forwards the gauze plugs may so inconvenience the operator as to prevent him completing the operation, which therefore may have to be delayed for at least a week. If, however, the sinus be injured at an early stage of the operation and the symptoms for which it is being performed are urgent, then, in spite of all difficulties, the antrum, at any rate, must be opened to permit of drainage, the operation being completed at a later date.

Injury to the facial nerve. The nerve may be injured in any part of its course within the tympanic cavity, or in its vertical course through the stylo-mastoid canal. To avoid this injury, curetting of the tympanic cavity should always be performed gently, and care should be taken not to chisel too low down,—the usual fault of the inexperienced.

Twitching of the face means that the nerve has been touched. If the patient be under deep anÆsthesia, it is difficult to say whether the nerve has been injured or divided. In a case of doubt, it is wiser to discontinue the anÆsthetic until the conjunctival reflex returns, when it can easily be demonstrated whether the facial nerve is affected or not.

If the injury be the result of curetting, it is wiser to do nothing. Recovery almost invariably takes place, owing to the fact that the paralysis has been caused by slight injury of the nerve. If, however, the nerve has been chiselled through, and the injury has occurred in its lower portion, it should be freely exposed over this area. The severed ends of the nerve should then be approximated and left in situ. In this case permanent paralysis is possible.

The after-treatment consists in avoidance of pressure in packing, the giving of strychnine internally, and faradism or galvanism to keep up the tone of the facial nerve and the muscles it supplies. Careful testing of the electrical reaction will show whether nerve regeneration is taking place or not. If the paralysis has existed for six months, and if in addition there be a definite reaction of degeneration, then the question of anastomosing the peripheral portion of the facial nerve to the spinal accessory, or what is more advisable, to the hypoglossal nerve, may be considered (see Vol. I, p. 452).

Injury to the labyrinth. Of the semicircular canals the external is the more liable to injury. The cochlea may also be injured from violent curetting of the promontory, or infected from dislodgment of the stapes; or it may even happen that a careless operator may inadvertently chisel through the promontory itself. In consequence of these accidents, vertigo, vomiting, and nystagmus may persist for several days, but as a rule they gradually diminish and disappear.

The treatment is expectant. As a result of pyogenic infection, suppuration of the labyrinth may occur. Even if this does not take place, complete deafness may result.

Injury to the dura mater. The subsequent danger is meningitis, fortunately a rare occurrence. The immediate treatment is to irrigate the part with weak biniodide of mercury solution, and then to remove more bone over the site of the injury. The intracranial pressure will keep the dura mater in close contact with the bone, so that if subsequent infection occurs there will be free drainage. The site of injury should be carefully isolated from the general mastoid wound cavity by covering it with sterilized gauze. If signs of meningeal irritation occur, the wound should be inspected, and if there be any evidence of localized meningitis, it should at once be surgically treated.

RESULTS OF THE OPERATION

With regard to life. If, at the time of the operation, the disease be limited to the mastoid cavity, there should be no immediate danger to life.

With regard to recovery. (i) The operation is successful. Roughly speaking this occurs in at least 80% of the cases, complete healing taking place within eight to twelve weeks. If skin-grafting has been successfully performed the duration of healing may be considerably shorter. If the bone disease has been eradicated with complete healing of the cavity, the possibility of intracranial complications in the future can be excluded. On this account the patient may be considered as a healthy individual from an insurance point of view.

(ii) The after-treatment may be prolonged. The chief causes of delay in healing and continuance of the suppuration are sepsis and caries of some part of the bony wall, usually the promontory or floor of the tympanic cavity, or around the orifice of the Eustachian tube. In the former case the use of ear-baths of hydrogen peroxide or of rectified spirit, or frequent syringing of the cavity with a weak biniodide of mercury solution, and afterwards drying it and protecting it with gauze, may be sufficient to effect a cure. In the latter case the local condition must be treated.

Another condition delaying cure is reinfection from the throat through a patent Eustachian tube. In this case, although the mastoid cavity becomes lined with epithelium, mucous membrane may still cover not only the region around the Eustachian orifice, but the main portion of the tympanic cavity. The chief object in these cases is to close the orifice of the Eustachian tube. Sometimes this can be done by curetting under cocaine; in other cases by actual cauterization. After closure has been obtained, the cavity should be dried and gently packed with gauze impregnated with boric acid or aristol powder.

Again, cholesteatomatous formation may be the immediate cause of relapses. In these cases it is very difficult to remove all the diseased tissue. Even although the patient may apparently be cured, yet, unless kept under close observation, recurrence of cholesteatomatous masses take place, and frequently cause further caries of the underlying bone.

Finally, delay in healing may be due to careless after-treatment: if the cavity has not been properly packed, granulations spring up in the region of the aditus and gradually form a partition between the mastoid and tympanic cavities. If this takes place, further disease of the bone may occur owing to the retention of the secretion.

(iii) Symptoms may occur pointing to some intracranial complication, and further operation may become necessary.

With regard to hearing. The hearing power depends not only on the condition before operation, but also on the result of the after-treatment. The average hearing power after the removal of the malleus and incus is about 12 feet off for ordinary conversation. The same result should be obtained after the complete mastoid operation, provided there be no internal-ear deafness and provided the stapes be not already ankylosed within the fenestra ovalis. If the patient before operation hears conversation at a greater distance than 12 feet he should be told that the hearing power may be reduced to this amount. If, however, there be considerable deafness, due to polypi or granulations blocking up the tympanic cavity and auditory canal, the hearing power may be improved by the operation. The ultimate hearing depends on the condition of the stapes within the fenestra ovalis: if it remains freely movable, the hearing power may be extremely good. The great object, therefore, of the after-treatment is to prevent the inner wall of the tympanic cavity becoming covered with granulations which may become organized later into a fibrous pad covering the inner wall of the tympanic cavity, and thus prevent movement of the stapes and, in consequence, marked deafness. The prevalent idea that the hearing power is destroyed irrevocably, as a result of the complete operation, is quite wrong: equally so is the harmful statement that, as a result of this operation, complete restoration of the hearing can be obtained.

CHAPTER VII
OPERATIONS UPON THE LABYRINTH

GENERAL CONSIDERATIONS

Labyrinthine suppuration usually occurs in the course of a chronic middle-ear suppuration; more rarely, as the result of tuberculous disease of the temporal bone, or in consequence of an acute middle-ear suppuration. In the latter case, however, it is a matter of experience that, although symptoms of labyrinthine suppuration may be present, they almost invariably subside as a result of drainage of the middle ear and mastoid. This is an important point which should be remembered, as otherwise the labyrinth may be explored unnecessarily at a considerable risk to the patient’s life.

The most frequent paths of extension of the pyogenic infection from the middle ear to the internal ear are through the external semicircular canal, the promontory, and the fenestra ovalis, the result of cholesteatomatous erosion, caries, or necrosis. Hinsburg, in 198 cases of labyrinthine suppuration, traced the infection in 61 cases. In 27 cases the infection had entered through the external semicircular canal, in 17 through the fenestra ovalis, in 7 through a fistula of the promontory, in 5 through the fenestra rotunda and ovalis, and in 5 through a fistula in the posterior or superior semicircular canal (Archives of Otology, 1902, vol. xxxi, p. 116).

Although operations on the labyrinth are practically limited to suppurative disease, yet under certain conditions they are justifiable when no suppuration is present.

These operations may consist in partial or complete opening of the semicircular canals, or of the vestibule, or in removal of the cochlea, or complete extirpation of the labyrinth.

INDICATIONS FOR OPERATION

(i) In non-suppurative labyrinthitis.

(a) To relieve vertigo. This operation is only justifiable if the condition cannot be cured by other methods, and is so distressing as to render the patient’s life unendurable.

In such cases it is first essential to make certain that the attacks of vertigo originate from some lesion within the semicircular canals. For this reason the other forms of vertigo must be excluded, and, in addition, there should be evidence of definite involvement of the labyrinth, such as falling over of the patient to the affected side, internal-ear deafness, or post-suppurative changes within the middle ear, suggestive that the internal ear has also become affected. It must, however, be remembered that it is possible, though extremely rare, for a lesion, limited to the semicircular canals, to produce marked vertigo without any deafness being present, in which case the operation will be limited to extirpation of the semicircular canals.

(b) To relieve tinnitus. If the tinnitus be unbearable and all other measures have failed to cure it, the question of extirpation of the cochlea, in order to destroy the nerve-terminals, may be discussed. This operation, so far, has not been completely successful, and therefore it cannot be recommended.

In this connexion it may be mentioned that, instead of attacking the cochlea, it has been proposed to divide the auditory nerve before it enters the internal meatus. Charles Ballance has recently described such a case.

The difficulty of this latter operation and the very slight chance of cure which it offers, owing to the tinnitus probably being central, are sufficient to raise the question as to whether such an operation is really justifiable.

(ii) In suppurative labyrinthitis. The object of the operation is to remove the infective focus and, by permitting drainage, to prevent further complications, such as meningitis or intracranial suppuration.

Before deciding the question of operation every means available should be used to determine: (1) whether the symptoms are merely the result of disturbance of the labyrinthine function in consequence of suppuration still limited to the tympanic and mastoid cavities; (2) whether the labyrinthine lesion is localized or general; (3) whether the labyrinthine suppuration is associated with some intracranial complication, more especially meningitis or cerebellar abscess.

Suggestive of labyrinthine suppuration are vertigo, vomiting, spontaneous nystagmus, and disturbances of the equilibrium. In the more acute cases there may be loud tinnitus, pyrexia, rapid onset of deafness (with inability to hear high tuning-forks and loss of bone conduction), facial paralysis, and deep-seated pain.

In addition much information may be gained by determining the character of the spontaneous nystagmus, if present, or whether nystagmus can be elicited by BÁrÁny’s caloric tests.

(a) If the ear be normal, there is no spontaneous nystagmus.

If, however, the ear be syringed with water above or below the body temperature, a rotatory nystagmus will be obtained if the patient’s head is kept in the erect position, or a horizontal nystagmus if the patient is lying in the horizontal position with the face upwards.

Syringing with hot water causes a nystagmus directed towards the ear syringed; syringing with cold water, away from the ear.

(b) If there be a localized labyrinthine lesion, and the function of the labyrinth is still maintained, the same results will be obtained on syringing. Care, however, must be taken that the syringing is not forcible, otherwise the caloric tests will be unreliable, as in these cases nystagmus may be produced on even slight increase of pressure within the external auditory canal, and with this there may be a sensation of giddiness and nausea.

Spontaneous nystagmus, however, will probably be present, and will be directed towards the affected side. This spontaneous nystagmus is greatly modified by the caloric tests, being strongly exaggerated on syringing with hot water, and weakened or arrested on syringing with cold water.

(c) If the function of the labyrinth be destroyed, as in suppurative labyrinthitis, nystagmus will not be produced as a result of the caloric tests, but the spontaneous nystagmus, if present, will be directed towards the opposite, the normal side.

These various tests must be taken in combination with the symptoms, and frequently are of extreme value in deciding whether operation is indicated or not.

The chief difficulty is to exclude the possible existence of a cerebellar abscess (see p. 460). In favour of labyrinthine inflammation is complete internal-ear deafness, although this in itself does not exclude an accompanying intracranial lesion.

1. Immediate exploration of the labyrinth is indicated (provided there is internal-ear deafness):—

(a) If symptoms of acute labyrinthine suppuration occur in the course of a middle-ear suppuration, even although at the time of opening of the mastoid no definite fistula of the labyrinthine wall can be discovered.

(b) If symptoms of involvement of the labyrinth be present and a definite fistula is found on operation.

(c) If symptoms of a cerebellar abscess or of meningeal irritation be present in addition to those suggestive of a labyrinthine affection.

2. Opening of the labyrinth should be delayed if BÁrÁny’s and other tests show that the labyrinth is not yet destroyed:—

(a) If, in spite of clinical symptoms pointing to involvement of the labyrinth, pus be found under tension within the tympanic cavity or the mastoid process.

(b) If the symptoms before operation consist only of attacks of vertigo and nystagmus, and on operation merely an erosion of the outer wall of the labyrinth (usually the external semicircular canal) is discovered.

In the above cases, if the symptoms be due to irritation of the labyrinth, a rapid recovery is to be expected as a result of the mastoid operation. If, however, they continue or become progressively worse, then the wound cavity must be reopened and the labyrinthine wall carefully examined and further operation undertaken.

The reader may again be reminded that although exploration of the labyrinth is indicated when it is certain that a suppurative lesion exists, yet it is a very serious mistake to open up a labyrinth not yet infected.

Although a great advance has been made in the last few years with regard to operations on the labyrinth, yet there is still much to be learnt, not only with regard to the indications for operation but the result obtained by operation. Now that operations on the labyrinth have become universal, the general tendency is to operate on the immediate occurrence of symptoms of labyrinthine irritation without waiting to see whether simple opening of the mastoid process will not be sufficient—a matter much to be regretted.

Surgical Anatomy. The facial canal, it will be remembered, extends horizontally backwards above the promontory, and passes downwards superficially to the inferior portion of the vestibule which lies between the fenestra ovalis below and ampullary ends of the external and superior semicircular canals above. The nerve then extends directly downwards towards the stylo-mastoid foramen, being situated deeply within the posterior meatal wall.

Of the semicircular canals the external is the most prominent, and the only one visible during the performance of the ordinary mastoid operation; its outer border forms the inner and lower boundary of the aditus, and can usually be recognized as a white eminence. The superior semicircular canal can only be seen on careful removal of the overlying bone; its ampullary end is found lying just above that of the external canal. It forms the highest point of the labyrinth, becoming fused with the innermost portion of the tegmen tympani, and is in such close relationship with the upper surface of the petrous bone as to cause a smooth elevation on its surface. It is at this point in the operation of removal of the semicircular canal that the greatest risk is encountered of breaking through the petrous bone and of injuring the dura mater.

The posterior semicircular canal lies at right angles to the external canal, and is best exposed by careful removal of bone just posterior to the latter (see Fig. 240).

The outer half of the first whorl of the cochlea is formed by the promontory. Anteriorly it is in close relationship with the carotid canal, whilst below it lies the dome of the jugular fossa. Medially the modiolus is only separated from the internal auditory meatus by a very fine rim of brittle bone, which can easily be broken; a mishap which may permit of escape of the cerebro-spinal fluid, and also of possible infection of the meninges through the internal meatus.

METHODS OF OPERATING

These operations may be divided into: (1) simple curetting away of a localized lesion of the labyrinthine wall; (2) opening up of the vestibule with removal of the semicircular canals; (3) opening of the cochlea; (4) a combination of these methods—extirpation of the labyrinth.

Curetting away of a localized lesion of the labyrinthine wall. It has been already stated that, provided the labyrinth be not yet destroyed, it is not justifiable to explore it on the mere discovery of an erosion of the semicircular canal. At the same time, if a definite fistula from which granulations protrude is present, a small fragment of bone may be chipped away, the granulations being afterwards removed by the curette. Unless pus is found to exude from the labyrinth, it is not necessary to do anything further at the present moment. If, however, at a later period, symptoms of labyrinthine infection occur, then it is necessary to further explore the semicircular canal and vestibule, the extent of the operation depending on what is discovered at the time of the operation.

Sometimes an examination of the tympanic cavity may be prevented before operation owing to the auditory canal being filled with polypi or granulations. On performing the complete mastoid operation and curetting away these granulations and polypi, a fistula may be found in the promontory, and carious bone may be felt on probing. Not infrequently these cases are tuberculous in origin and are accompanied by facial paralysis. Provided there be no labyrinthine symptoms, it is sufficient to curette out the granulations, but only gently. Violent curetting may break through the barrier between the infected area and the internal meatus and so lead to meningitis. It is wiser to curette too little than too much.

A further condition which may be met with is necrosis of a portion of the promontory, or of the walls of the vestibule, or of the semicircular canals. If the sequestrum be not quite loose at the time of operation, it should be left in situ, provided there be no intracranial symptoms. In fact, there is less danger in leaving the sequestrum than in attempting to remove it. After the operation, the wound cavity is kept open, so that the sequestrum can be removed at a later date after it has separated from the living bone.

Opening the vestibule (with partial or complete removal of the semicircular canals). This may be performed by one of the following methods:—

Above and behind the facial nerve through the semicircular canals. The complete mastoid operation is performed first. The chief difficulty is to expose the field of operation so as to obtain sufficient room for the necessary manipulations. To do this the following steps should be carried out: The tip of the mastoid process and the remains of the posterior wall of the auditory canal are removed to their extreme limit without injury to the underlying facial nerve. The floor of the auditory canal is also chiselled away until the lower level of the tympanic cavity is brought freely into view, the amount of bone removed depending on the anatomical condition found. To expose the anterior portion of the tympanic cavity, the skin incision is extended slightly forwards, but not far enough to wound the temporal artery, the soft tissues being then separated from the bone and the auricle pulled still further forwards and downwards.

Skin meatal flaps are now fashioned—either the Y-shaped flap or Stacke’s flap (see p. 403)—and are afterwards kept in position by means of sutures. Good illumination is necessary, and for this reason a head-light should be used. One assistant is employed to retract the soft tissues from the wound, another to keep it as dry as possible.

The exposed portion of the external semicircular canal is first identified. If the bone be soft, the arches of the semicircular canal should be defined (Fig. 240). The posterior canal will be discovered by gouging away the bone just posterior to the arch of the external semicircular canal, and the superior, by working inwards and upwards towards the roof of the attic. If the outline of the canals can be made out, the further steps of the operation are rendered very much easier. Unfortunately, the bone is sclerosed in the majority of cases, rendering anatomical exposure of the canals an impossibility.

The next step is to remove the eminence of the horizontal semicircular canal. This is best done by means of a small gouge and mallet. Some prefer a burr, specially constructed to cut vertically; others a chisel. I prefer a fine gouge. As the facial canal runs along the lower anterior portion of the external semicircular canal, the gouge should be directed in a backward direction in removal of the outer wall of the latter, so as to cut away from the facial canal.

The surgeon should be content to remove the bone piecemeal, as, owing to its brittleness, it is very apt to splinter, or the point of the gouge itself may slip and so injure the facial nerve.

After an opening has been made into the canal, it should be enlarged by following the canal forward until its ampulla is reached. After this has been done, a fine probe, bent at a right angle (Schwartze’s seeker will do very well), is passed into the opening, and the limits of the vestibule made out as far as possible. The bone is then removed in an upward direction until the ampulla of the superior canal is reached. The opening may then be extended backwards so as to remove the outer wall of the vestibule, that is, the portion of bone which lies between the ampullÆ of the superior and external canals.

If the bone be sclerosed, so that it is impossible to find the superior and posterior canals, then, after opening the exposed portion of the external semicircular canal, the bone should be chiselled away at the area marked out in Fig. 240. By this means the vestibule will certainly be reached, and from this point its opening can be extended in any given direction. A sufficient opening should be made so that the inner portion of the vestibule can be seen (Fig. 241). During each step of the operation a clear view must be obtained.

Not infrequently the facial nerve is exposed or pressed upon in chipping away the outer wall of the external semicircular canal, as will be shown by sudden twitchings of the face. If the surgeon be careful, and works in a direction away from the nerve, it should not be injured. If possible, the outer margin of the horizontal semicircular canal, together with the Fallopian canal, should be left intact as a bridge crossing the vestibule. If necessary, the external and superior canals can be removed in their entirety. A fine probe is inserted into the lumen of the canal so as to tell its direction, and its outer wall is then burred away. For this particular purpose a burr should be used as soon as the surgeon has got beyond the region of the facial nerve. After a view of the interior of the vestibule has been obtained, the ampullary nerves may be destroyed by means of the curette or with pure carbolic acid at the end of a probe. Removal of the posterior canal is best effected by opening it just behind the external semicircular canal and following it out in an upward direction until it meets the superior, and then downwards until it enters the vestibule. This extensive operation is one of extreme difficulty and seldom necessary.

Posterior to the semicircular canals: Neumann’s method. Neumann enters the vestibule posteriorly. The bone forming the inner wall of the antrum is removed by means of bone forceps or gouge and mallet until the posterior semicircular canal is opened. By this means the posterior surface of the petrous bone can be exposed as far inwards as the internal auditory meatus.

Below and anterior to the facial nerve through the promontory. The preliminary steps of the operation having been performed and the field of operation freely exposed, the stapes, if still present, is extracted by means of a small hook passed between its crura. The bridge of bone between the fenestra ovalis and fenestra rotunda is then cut through by light taps on a very fine gouge. The bone is removed by attacking the lower limit of the fenestra ovalis, and working downwards until the fenestra rotunda is reached. With a fine curette or scoop the loosened fragments of bone are removed. Care must be taken not to work above the region of the fenestra ovalis or the facial nerve will probably be injured. After a sufficient opening has been made, a bent probe can be passed through the opening in the promontory in an upward and backward direction behind the facial nerve into the inferior and anterior portion of the vestibule (Fig. 241).

Removal of the cochlea. If necessary, the first turn of the cochlea can now be removed by gouging away the promontory from behind forwards. If the anterior wall of the external auditory canal interferes with this being done, it may be partially removed by means of the gouge and mallet. After the first half-turn of the cochlea has been opened, its contents may be curetted out, care, however, being taken to avoid the carotid canal, which lies in close relationship with its anterior inferior portion. If the bone be carious only gentle curetting is necessary. If, however, this be not the case, simple curetting may not be sufficient, and the gouge and mallet may have to be used. To destroy the cochlear nerve, the whole of the cochlea should be removed. This is sometimes a difficult matter to determine. If the operation be done for the relief of tinnitus, then, after as much as possible of the cochlea has been removed, the interior may be swabbed out with strong carbolic acid solution, which should set up sufficient inflammatory reaction to destroy the nerve-terminals.

Extirpation of the labyrinth. This consists in the removal of the semicircular canals, and opening of the vestibule and cochlea, the steps of which have already been described in the above operations.

Before the operation is completed, the inner wall of the vestibule and the cochlea should be carefully examined for fistulÆ, and in order to see if any pus enters these cavities from within. If this be the case it means that, in addition to labyrinthine suppuration, there is presumably an extra-dural abscess of the posterior intracranial fossa, drainage of which is essential in order to obtain a recovery.

After the operation has been completed, the cavity should be filled with hydrogen peroxide, then gently syringed out with weak biniodide solution, and finally dried and lightly packed with sterilized gauze.

Even although the operation may have been performed in a non-suppurative case, it is wiser to leave the posterior wound open for the first few days in order to permit of free drainage.

After-treatment. If the suppuration has been limited to the internal ear, a successful result may be expected if the symptoms subside rapidly as a result of the operation. If there be complete destruction of the labyrinth before operation its performance should give rise to no symptoms of shock nor further disturbance of equilibrium.

In the majority of cases, however, owing to the nerve-terminals being still in a state of activity, the irritation set up as a result of the operation may cause increased attacks of nystagmus, vertigo, and vomiting. The vomiting is the first symptom to disappear, and then the nystagmus; but complete recovery of equilibrium may not occur for a considerable period, during which time the patient, though otherwise well, may still have a slightly staggering gait.

If the operation has been limited to the external semicircular canal, and the hearing power still exists, the after-treatment should be carried out as already described in the complete mastoid operation. If, on the other hand, the cochlea has been interfered with, or if it be certain that there is no longer any hearing power, then there is no object in trying to preserve the patency of the tympanic cavity, which in this case may be allowed to granulate up from its depth like an ordinary surgical wound.

The immediate anxiety of the surgeon after the operation is the possible onset of meningitis or the presence of a cerebellar abscess, which will necessitate further operation unless otherwise contra-indicated (see p. 460).

Comparison of the operations. Opening of the vestibule above the facial nerve is limited to those cases in which the lesion is situated within the semicircular canals and to the posterior portion of the vestibule; that is, either in non-suppurative cases in which the operation is performed in the hope of curing vertigo, or in suppurative cases in which the function of hearing still exists.

Opening of the vestibule below the facial nerve is to be preferred as a rule, especially if the function of hearing is already destroyed, because it permits of drainage from the inferior part of the vestibule; in addition, by working forwards, the outer wall of the cochlea can be removed and any disease within it can be tracked out to its limits.

If there be suppuration within the cochlea, sufficient drainage will not be obtained by merely opening the vestibule through the semicircular canals, but the cochlea itself must be opened. Again, if the lower portion of the vestibule and cochlea be first explored and found filled with purulent secretion, it is wiser to complete the operation by also opening the vestibule from above,—that is, to completely extirpate the labyrinth, which is now functionally useless and almost certain to be infected throughout its whole extent.

Intracranial complications. If, in addition to the labyrinthine suppuration, intracranial suppuration be suspected, the labyrinth should be explored first; but when possible the operation should be arrested at this point to see if the symptoms subside. If they continue, the exploration of the intracranial cavity can then take place through the internal ear, after a delay of twenty-four hours or more.

Of the intracranial complications, meningitis is most frequent, and next in order cerebellar abscess. In addition, thrombosis of the bulb of the jugular vein may take place from infection through one of the smaller tributary veins; or a localized extra-dural abscess may be found situated along the posterior portion of the petrous bone in consequence of direct extension of the infection through the internal auditory meatus, or as a result of empyema of the endolymphatic sac. This latter condition is almost impossible to diagnose, but may be discovered accidentally if the vestibule is opened by the posterior route according to Neumann’s method.

Difficulties. The chief difficulties are anatomical, and the inability to obtain a clear view owing to general oozing of blood.

The first is generally due to insufficient removal of bone; the second can usually be controlled by means of good assistants and the frequent employment of hydrogen peroxide or of adrenalin solution.

Dangers. Injury to the facial nerve. This, as might be expected, is not infrequent. If a burr be used, the nerve may be completely torn across and permanent paralysis may result. If, however, the gouge and mallet be employed, complete recovery usually takes place, as the injury seldom consists in complete destruction of the nerve.

Opening up of the internal meatus. This may be accompanied by a gush of cerebro-spinal fluid. There is nothing to be done except to try and keep the part as clean as possible and see that there is free drainage. Undoubtedly, as a result of this mishap, death has afterwards occurred in consequence of septic meningitis.

Injury to the internal carotid or bulb of the jugular vein. These are possibilities which, however, should not occur if ordinary care is taken.

Prognosis. The prognosis of labyrinthine suppuration is always grave, owing to the frequency of intracranial complications.

The most favourable cases are those in which the disease is localized and is of chronic duration. The most unfavourable are those in which acute suppurative labyrinthitis is accompanied by extensive bone disease.

According to statistics, the mortality is about 50% in cases not operated upon. As a result of operation, this has been reduced to less than 20%, and in the majority of these cases the ultimate fatal result cannot be put down to the operation itself. The patient is frequently seen too late, that is, after intracranial complications have already occurred. There is no doubt that the death-rate will diminish proportionately according as the necessity of operating early becomes more and more recognized.

With regard to hearing, extensive operations upon the labyrinth lead to complete deafness; nor, indeed, can recovery of hearing be expected except in those cases in which the disease and operations have been limited to the semicircular canals and to the posterior portion of the vestibule, and even then recovery of hearing is exceptional.

CHAPTER VIII
OPERATIONS FOR EXTRA-DURAL ABSCESS AND MENINGITIS
OF OTITIC ORIGIN

ON INTRACRANIAL COMPLICATIONS IN GENERAL

As the intracranial complications of otitic origin are due to direct extension of the pyogenic infection through the temporal bone to the cranial cavity, it follows that they will depend on the extent of the disease within the temporal bone, the direction in which it has spread, and the virulence of the infection. For this reason, also, the site of the intracranial lesion is always in close relationship with the area of the diseased bone. Thus, if the infection spreads upwards through the attic and tegmen tympani, it may lead to extra-dural abscess or to meningitis of the middle fossa, or to a temporo-sphenoidal abscess. Similarly, disease of the mastoid cells posteriorly may give rise to a perisinuous abscess, to meningitis of the outer surface of the posterior fossa, to lateral sinus thrombosis, or to a cerebellar abscess situated superficially and involving the outer portion of its lateral lobe just behind the lateral sinus; or caries of the floor of the tympanic cavity may give rise to thrombosis of the jugular bulb; or internal-ear suppuration to an extra-dural abscess occupying the posterior surface of the petrous bone, to meningitis of the posterior fossa, or to an abscess of the cerebellum deeply placed in its anterior inferior angle.

Operation is always imperative unless the patient is seen too late and it is obvious that the condition is hopeless.

Before operation is decided on the following points must be carefully considered: (1) Is it possible that the symptoms simulating the intracranial lesion are due to suppuration still limited to the temporal bone? (2) What is the character of the lesion? and (3) What is its situation?

As a rule, so long as the suppurative process is limited to the middle ear and to the mastoid region, the symptoms are those of a local septic infection. At the same time it must be remembered that in infants and in young children it is not uncommon for retention of pus within the middle ear to produce a clinical picture closely simulating an intracranial suppurative lesion. The ear, therefore, should always be inspected in every case. Sometimes a bulging membrane is discovered or the existing perforation is found to be insufficient for drainage. In such cases the symptoms may subside on free drainage being obtained by the simple act of paracentesis of the tympanic membrane.

If, however, free drainage already exists, the mastoid operation should be performed at once.

If the intracranial symptoms be still somewhat indefinite, and there is no apparent urgency, the intracranial cavity should not be explored immediately unless this is found to be imperative at the time of operation. This can be done later, if the symptoms do not subside.

Although exploration of the intracranial cavity is always urgent when it is certain that an intracranial suppurative lesion is present, yet to explore with a negative result is a grave misfortune, owing to the possibility of infecting the intracranial cavity.

Although the surgeon may be certain that an intracranial lesion is present, yet it may be very difficult to determine its character or whether several lesions coexist. The surgeon must therefore be prepared to act according to what he finds at the time of operation.

Thus, if exploration of the temporo-sphenoidal lobe be negative, and yet the cardinal symptoms point to an intracranial abscess, the cerebellum must also be explored. Again, if the diagnosis of intracranial abscess be doubtful before operation, and if, during the operation, lateral sinus thrombosis be discovered, it is wiser to limit the operation to tying of the jugular vein and removal of the septic thrombus. The bone, however, should be removed above and behind the sinus so as to expose the dura mater covering the temporo-sphenoidal lobe and the cerebellum.

In such cases, if the symptoms of intracranial suppuration still continue, it is an easy matter to explore the temporo-sphenoidal lobe or cerebellum at a subsequent operation.

Although under exceptional circumstances (see p. 461) it may be justifiable to open an intracranial abscess by directly trephining the skull over it, yet free opening of the mastoid process should be the first step in the operation, as the primary focus of the disease exists within the temporal bone. In addition, much information may thus be gained in a doubtful case with regard to the situation of the intracranial lesion.

OPERATIONS FOR EXTRA-DURAL ABSCESS

This is far more common as a sequel of acute than of chronic disease of the mastoid process.

Indications. Operative interference is indicated in order to permit of drainage. An extra-dural abscess is frequently discovered accidentally, especially if the surgeon follows out the golden rule to trace any patch of carious bone to its limit. In doing so he may suddenly meet with a gush of purulent discharge coming through an opening in the bone in the region of the tegmen tympani or sigmoid sulcus.

Although an extra-dural abscess may give rise to no special symptoms, the following are suggestive:—

1. If, in spite of opening up the mastoid cells and antrum, pyrexia and headache persist, especially if the headache be localized to the affected side and accompanied by tenderness on pressure above the ear or behind the mastoid process.

2. If, before operation, there be a very profuse discharge from the ear, apparently too copious to come from the tympanic cavity or mastoid antrum.

3. In children an extra-dural abscess may give rise to symptoms of cerebral irritation or compression if it extends upwards from the tegmen tympani along the parietal region; or, if situated in the posterior fossa, to retraction and stiffness of the neck.

Although such symptoms may be also associated with an intracranial abscess or meningitis, yet, if on exploration of the intracranial cavity a large extra-dural abscess be discovered, further operation may be postponed (unless its extension is obviously necessary) until time is given to see whether the symptoms will subside or not.

Operation. If the mastoid process has not been opened already, the simple or the complete operation is performed, according to whether the suppuration is recent and acute, or is of long standing.

If, however, this has been done, the wound is reopened, all granulations are curetted away, and the cavity is cleansed and dried.

The antrum and mastoid cavity are then thoroughly examined. If a fistula in the bone already communicates with the abscess, pus may be seen to ooze through it. If not, careful search is made for any carious tract of bone, which is now followed up until the dura mater is reached.

After the pus has drained away more bone is removed so as to expose the dura mater fully over the infected area, which is usually vascular or covered with granulations. The latter, however, should be left severely alone. If the abscess be situated in the middle fossa above the tegmen tympani, the bone is best removed by chiselling upwards until the lower margin of the squamous portion of the temporal bone is reached. Then, with a pair of bone forceps, more bone can be punched away quickly until a sufficient opening is obtained (Fig. 243).

Exploring with the probe and curetting away of granulations should be avoided as far as possible for fear of injuring the sinus. If its wall be already inflamed, it may be torn through, and the resulting hÆmorrhage may render the further steps of the operation a matter of extreme difficulty.

Before completion of the operation, a blunt-pointed seeker should be passed round the edge of the opening in the bone to see that its margin is smooth and even, and all sharp edges of bone bordering on the dura mater should be removed. If this precaution be neglected, a splinter may get pressed inwards and injure the dura mater, and thus set up meningitis.

If possible the bone should be removed until the healthy dura mater is reached. If the extent of the abscess prohibits this, its limits, however, should be ascertained. This can be done by pressing the dura mater inwards with a spatula so as to separate it from the overlying bone.

The final step is to irrigate the cavity with warm boric or saline solution and to insert drains of gauze or of fine india-rubber tubing between the dura mater and bone. The wound cavity is then lightly packed with gauze and a simple dry dressing applied.

After-treatment. Provided there be no other intracranial symptoms, recovery should be as rapid as in the case of simple inflammation of the mastoid process. In the after-dressings, however, special care should be taken not to press in the gauze roughly or tightly against the still inflamed dura mater, in case of injuring its surface and causing further extension of the pyogenic infection to the meninges or lateral sinus. The dressings should be changed daily. It is sufficient to irrigate the wound with some mild aseptic lotion and afterwards to repack it lightly. If Schwartze’s operation has been performed, the after-treatment is similar to that already described (see p. 387). In the case of the complete operation, after the purulent discharge has practically ceased and the surface of the wound appears healthy, the packing of the cavity may be carried out through the meatus, instead of through the posterior wound, the latter being then allowed to close.

Intracranial complications. Infection of the lateral sinus is the most frequent complication, but meningitis, ulceration of the surface of the brain, or intracranial abscess may also occur.

One or more of these complications may already exist at the time of operation, but may not be sufficiently marked to warrant further exploration of the intracranial cavity. It is wiser, therefore, to give a guarded prognosis during the first few days after the operation, not only with regard to recovery, but also to the possibility of further operative procedures becoming necessary.

OPERATIONS FOR MENINGITIS OF OTITIC ORIGIN

Formerly the onset of symptoms of meningitis was a distinct contra-indication to operation. More recently, however, this view has become modified, especially as it has been shown definitely by Macewen, Jansen, Brieger, and others that recovery is possible if operation is undertaken sufficiently early before the inflammation of the cerebral membrane has become diffuse.

In this connexion must be mentioned—(1) Serous meningitis: a name given to an increase of the cerebro-spinal fluid within the subdural or subarachnoid space, or the ventricles, the hypersecretion being probably caused, as Merkens suggests (Deutsche Zeitsch. fÜr Chir., vol. lix), by the toxic infection induced by the suppurative focus in contact with the external surface of the dura mater. The symptoms of serous meningitis may closely simulate an intracranial abscess or a purulent meningitis, except that frequently there is no pyrexia. (2) Purulent meningitis, which may be diffuse or localized. (3) Pseudo-meningitis: that is, a condition simulating meningitis but in reality due to irritation of the meninges as a result of suppuration still confined within the temporal bone—for example, the result of acute middle-ear suppuration in infants.

Clinically it is often difficult to determine before operation which variety is present.

Indications. Operation is indicated as soon as the onset of meningitis has been diagnosed and should be performed without delay. Waiting for all the cardinal symptoms of meningitis to occur will never save life. The only possibility of doing so is to operate while the inflammatory process is still localized. At the same time it must be recognized that whenever symptoms of meningitis occur the prognosis is most serious.

Lumbar puncture should always be performed as an aid to diagnosis. If the cerebro-spinal fluid be clear and sterile, diffuse meningitis can usually be excluded, although at the same time it must be remembered that it does not negative a localized meningitis without increased intracranial pressure. Increased flow of cerebro-spinal fluid indicates increased intracranial pressure, perhaps the result of serous meningitis. Slight turbidity suggests early purulent meningitis, especially if bacteria are present, but not necessarily that the case is hopeless. If the fluid be definitely purulent, operation may be considered out of the question; a case, however, has been recorded in which recovery took place.

The value of cytological examination of the fluid is still doubtful. Marked increase of polynuclear cells is said to point to acute and intense inflammation, whereas an abatement of the polynucleosis may be taken as a sign of diminution of the meningeal irritation. With this, increased leucocytosis, increasing as recovery progresses, may be looked upon as a hopeful sign.

If it be obvious that the patient is dying, not only from the local infection but also on account of general septic absorption, operation, of course, is excluded. Similarly, at the present time, post-basic meningitis of infants is rightly deemed inoperable.

Operation. Although no set operation can be described, the principles of the operation are to expose the infected area widely so as to allow of free drainage and, at the same time, to relieve intracranial pressure. The extent of the operation will therefore depend largely on what is found during the course of the operation itself.

1. In an infant or young child, if the symptoms develop in the course of an acute otitis media, the tympanic membrane should first be inspected to see if there is sufficient drainage. If not, it should be freely incised, and opening of the antrum and mastoid may be delayed for at least twelve hours.

2. In an adult, immediate exploration of the mastoid and antrum is indicated on the onset of meningeal symptoms, even although they occur during the course of an acute middle-ear suppuration.

If the symptoms of meningitis in these cases be as yet indefinite, and if pus be found under tension within the mastoid cavity, or if an extra-dural abscess exists, the dura mater should not be incised at once, but a delay of twenty-four hours should be advised; in many cases complete recovery will take place. If, however, the symptoms continue, intracranial exploration will be necessary.

3. In chronic middle-ear suppuration, meningitis is usually secondary to, or accompanies, other intracranial complications or internal-ear suppuration, the symptoms of which it may mask.

After performing the mastoid operation any tract of carious bone is followed out to its limits.

According to what he finds, the surgeon may first expose the dura mater covering the lower portion of the middle fossa (Fig. 243), or of the posterior fossa behind and in front of the lateral sinus; these are the usual sites of infection. The removal of bone must be free, in order to get well beyond the limits of the infected area, if possible. The dura mater is incised to the limits of its exposure either crucially or by cutting it through in the form of a large flap.

The dura mater is usually congested, but if an extra-dural abscess or lateral sinus thrombosis be present, it may be thickened and of a leathery appearance; or in the latter case almost gangrenous.

The further steps depend on the conditions met with on incision of the dura mater.

1. In serous meningitis a certain amount of clear fluid may escape and the brain surface may be only slightly congested. After removal of the bone and of the dura mater over the infected area the surface of the brain should be scarified in various directions to make certain that the pia-arachnoid has been incised, and fine drainage tubes should be inserted between the latter and the dura mater. In these cases a hernia seldom occurs, although the brain surface may bulge slightly into the wound.

2. In purulent meningitis the surface of the brain is usually covered with turbid fluid or purulent lymph, which may be localized to the site of the diseased bone, or may have spread from this point to a varying extent over its surface.

If the limit of the infection cannot be reached, in spite of removal of a considerable extent of bone and dura mater, all that can be done is to irrigate the exposed area with warm saline solution and to insert fine drainage tubes between the brain and dura mater, at the same time (as in the case of serous meningitis) incising the meninges in various directions.

3. Purulent lepto-meningitis is usually accompanied by encephalitis. If localized by adhesions an accumulation of pus may occur, forming an abscess on the surface of the brain, which also may be superficially ulcerated or necrosed. If there be intracranial pressure from encephalitis, the brain tissue usually protrudes as a dark, hÆmorrhagic friable mass, in which shreds of necrotic brain tissue will be seen. In other cases, if there be no increased intracranial pressure and if the condition be quite localized, no hernia may occur, but the surface of the brain may be rough or eroded.

Any purulent secretion should be removed by irrigation, care being taken not to disturb the brain more than is necessary, so as to diminish the risk of breaking down the surrounding adhesions. A hernia may or may not form immediately. If no hernia takes place, it is wiser to do nothing further; that is, provided sufficient bone and dura mater have been removed to reach the limits of the infected area. Some authorities, however, consider that the necrosed portion of the brain should be curetted out. Although in other parts of the body the removal of necrosed tissue is a proper procedure, yet in the case of the brain there is considerable risk of setting up further oedema or septic cerebritis, the progress of which may have become arrested at the time of the operation.

If the inflamed brain tissue protrudes to an excessive degree during the operation itself, the opening in the skull should be enlarged, if it be not already of considerable magnitude, and the dura mater incised to the full limits of the opening. The protruding mass may then be cleanly excised by means of a scalpel. If, however, the brain tissue continues to prolapse, the wound cavity should be simply cleansed and protected by a dressing of sterilized gauze. If the encephalitis subsides, the hernia will not increase in size, and if the wound cavity be kept aseptic, it may gradually shrink.

After-treatment. This consists in covering the wound surface lightly with gauze so as to permit of free drainage, and changing the dressing as often as may be necessary.

In serous meningitis a large quantity of cerebro-spinal fluid may escape, and the dressings must be changed frequently. If recovery be going to take place, the temperature gradually becomes normal and the symptoms of meningitis disappear. In involvement of the posterior fossa, the head retraction gradually diminishes and after a few days free movement is noticed. Adhesions form rapidly, binding together the surface of the brain, meninges, and the overlying bone. For this reason the drainage tubes, already inserted between the dura mater and brain, can be removed within a day or two. The exposed dura mater usually becomes covered with granulations from which a certain amount of purulent discharge may be secreted. The duration of the after-treatment depends on the extent of the operation and the size of the wound. Eventually the skin flaps grow together and cover the brain, which afterwards may be felt pulsating through the scar. In these cases it is usually necessary to provide the patient with some protection, such as an aluminium plate.

If, however, a hernia forms and gradually increases in size, the brain should be explored again to see if another abscess can be discovered; or the lateral ventricle itself may be tapped in case of it being distended with fluid. Both these operations, however, must be looked upon as extreme measures.

If the patient otherwise recovers and a hernia still persists, the question arises what to do. Conservative treatment should first be employed, aseptic dressings being maintained, and slight pressure applied with compresses soaked in rectified spirits. If these measures fail, then the projecting portion of the hernia may be excised (see Vol. III).

Other methods. In addition, the following methods of treatment have been suggested. Although many failures have occurred in proportion to the few successful cases published, yet they show the possibility that something can be done by operative measures, and that considerable advance has been made in recent years in this direction.

(i) Repeated lumbar puncture. In a few cases of serous meningitis this has proved successful in that it has relieved intracranial pressure. It is, however, only of value if free communication still exists between the spinal theca and subarachnoid space.

(ii) Continuous drainage from the spinal canal. Friedrich, of Kiel, has suggested a counter-opening in the spinal canal by means of laminectomy in order to permit of drainage of the entire dural sac.

(iii) Puncture of the lateral ventricle. The temporo-sphenoidal lobe is pierced with a trocar, just above the zygomatic ridge, until the ventricle is reached; this has been performed frequently in order to relieve intracranial pressure. I know of only one recorded instance in which recovery has taken place in spite of there being pyogenic infection of the lateral ventricle; a fact which was proved by tapping the ventricle and removing from it a drachm and a half of purulent fluid (Archives of Otology, vol. xxxv, p. 535).

(iv) Drainage through the internal ear. West and Scott have recently described a case of meningitis which occurred after having curetted the inner wall of the tympanic cavity. They then opened up the labyrinth and inserted a wire drain through the internal auditory meatus, at the same time making a counter-opening in the lumbar region, through which they drained the spinal canal. The patient, a child, ultimately recovered.

Prognosis and after-results. Unless saved by operation, meningitis is almost uniformly fatal. Even if the patient recovers, whether as the result of operation or not, deaf-mutism or mental deficiency frequently occurs. In a few cases, however, complete recovery has taken place.

CHAPTER IX
OPERATIONS FOR LATERAL SINUS THROMBOSIS
OF OTITIC ORIGIN

GENERAL CONSIDERATIONS

The sigmoid portion of the lateral sinus is the part usually infected. Thrombosis, however, may occur primarily in the region of the jugular bulb from direct extension of the pyogenic infection through the floor of the tympanic cavity; this, though less frequent than involvement of the sigmoid sinus, is not so rare as has hitherto been supposed.

Operative treatment is imperative as soon as septic thrombosis of the sinus has been diagnosed. This, however, is not always an easy matter. Sometimes, indeed, there are no clinical symptoms, the condition perhaps only being discovered whilst performing the complete mastoid operation as a prophylactic measure. The sinus is generally exposed accidentally whilst following out a tract of carious bone, and, to the surprise of the surgeon, pus or granulations may be seen to exude or protrude from an opening in its outer wall. On further exposure of the sinus on each side of the thrombus, the dura mater may appear to be of a dark colour for a short distance, but beyond this to be of normal appearance.

Seeing that there are no symptoms, the presumption is that the sinus is occluded on each side of the septic thrombus by a non-infective clot. It is, therefore, sufficient in such cases to simply excise the sinus wall over the septic area. If the case be so treated, it is essential that the sinus should only be curetted gently over the exposed opening, but otherwise left undisturbed. Also this limited operation should only be performed if the surgeon is satisfied that the septic focus is surrounded on each side by an organized normal clot—the condition in fact being treated as a simple abscess.

To secure free drainage, only the depth of the mastoid wound should be packed with gauze, the surface being protected by a simple dry dressing. The after-treatment is the same as that already described for the complete mastoid operation in which the posterior wound has been left open.

In other cases, if there be an acute inflammation of the mastoid process and if only one rigor has occurred, it may not necessarily mean that thrombosis of the sinus has taken place, as the rigor may be due simply to septic absorption. In such cases it is justifiable to delay opening the sinus if it is found to be exposed within the wound cavity and to be covered with granulations.

The bone, however, should be freely removed until the normal dura mater is reached, and the cavity afterwards rendered as aseptic as possible by syringing it out with hydrogen peroxide lotion. In a large proportion of cases a favourable result occurs, the pyrexia and head symptoms disappearing and an uneventful recovery taking place. On the other hand, gradually increasing pyrexia or a sudden rigor may occur, perhaps not until ten days or so after the primary operation, showing that the sinus has become infected after all. It should then be opened at once, but before doing so the jugular vein should be tied (see p. 448).

In a typical case, however, there is a history of repeated rigors, and in addition there may be attacks of vomiting and headache localized to the affected side, with pain and tenderness on pressure behind the mastoid process, and optic neuritis. In the more severe cases there may also be evidence of thrombosis of the jugular vein or cavernous sinus. It must, however, be remembered that a high and intermittent pyrexia, especially in children, may take the place of rigors. The principles of surgical treatment are to expose the sinus and remove the infective clot completely.

In connexion with this operation two points cannot be impressed too forcibly on the reader:—

1. The operation must be performed at once. The greater the experience of the surgeon the more he realizes that expectant treatment is nearly always fatal, and that a successful result depends largely on early and complete operative measures.

2. Before the sinus is interfered with in any way it is essential to obliterate its lumen below the thrombus in order to prevent any portion of it being swept into the circulation during its removal.

EXPOSURE OF THE LATERAL SINUS

Indications. (i) In doubtful cases to decide whether thrombosis exists or not.

(ii) As a preliminary to opening the sinus with or without ligature of the jugular vein.

Operation. The first step is to perform the complete mastoid operation, except in the case of acute inflammation of the mastoid process, when Schwartze’s operation will be sufficient.

To expose the field of operation more freely, an incision an inch or more in length is made horizontally backwards, beginning at the mid-point of the posterior margin of the primary incision (Fig. 216), the soft parts being reflected upwards and downwards from the bone, and the flaps so formed being then retracted. Above, the bone should be exposed beyond the level of Reid’s base-line, which roughly corresponds to the line of the transverse sinus; below, the tip of the mastoid should be cleared until the mastoid vein is reached. If it be thrombosed it may be assumed that the lower part of the lateral sinus is also thrombosed. Bleeding from the bone at this point may be arrested by temporarily plugging the foramen with a fragment of sterilized wax.

The condition found on opening the mastoid process varies considerably. If the result of acute inflammation of the mastoid process, the mastoid cells surrounding the sigmoid sinus usually contain pus or granulations, on removal of which a fistula may be seen to communicate with the outer wall of the sinus; or the bone around the sigmoid groove may already be destroyed, with free exposure of the sinus within the wound. With this there is frequently an extra-dural abscess. In other cases, if the infective process has been very virulent, evil-smelling pus, sometimes intermixed with bubbles of gas, may escape on chiselling through the mastoid cortex. This is a sure sign of extensive disease, the sinus wall often being gangrenous and the bone surrounding it necrosed and discoloured.

If occurring in the course of a chronic middle-ear suppuration, very little disease of the mastoid process may be found except along the path by which the infection has spread.

After the sinus wall has been reached, sufficient bone should be removed to expose its outer surface for at least half an inch above and below the supposed infected area.

The decision as to whether thrombosis exists or not may have to be made during the operation itself, and is based partly on the appearance of the sinus wall and partly on the symptoms, the relative value of each varying in each individual case.

Normally the sinus pulsates and is of a bluish-grey colour. If thrombosed, the wall of the sinus may be of a yellow or dark colour and may not pulsate, but neither discoloration nor the absence of pulsation is an absolutely reliable sign of thrombosis. Again, if the sinus be covered with granulations or purulent lymph, it is sometimes impossible to say whether it is thrombosed or not, especially if the clot is limited and parietal. Further, the thrombus may be situated low down towards the jugular bulb, so that if it has not extended very far upwards the exposed portion of the lateral sinus may still be normal in appearance. Palpation of the sinus with the finger or aspiration with a hollow needle is sometimes advised as an aid to diagnosis. These procedures, however, are extremely unwise, owing to the risk of dislodging a small fragment of the infected clot, which may easily occur if the latter does not obliterate the sinus completely. As a means of diagnosis the withdrawal of blood by the aspirating needle is of no value, as it does not negative the presence of a parietal thrombus, owing to the possibility of the needle passing through it into the free lumen of the sinus.

OPENING OF THE LATERAL SINUS

Indications. The sinus should always be opened as soon as it is certain that septic thrombosis has occurred.

Contra-indications. The only contra-indication for opening the sinus and removing the thrombus is the certainty that either the patient’s general condition will not permit of the operation being performed, or that the septic thrombosis has spread beyond the region from which it is possible to remove it.

For this reason, operation is unjustifiable if the patient is already suffering from septic pneumonia, pericarditis, or acute septicÆmia; or, on the other hand, if there are symptoms of cavernous sinus thrombosis on both sides, or general meningitis. If, however, the patient’s general condition be good, operation may be attempted as a last resource even although a pulmonary empyema or a one-sided cavernous sinus thrombosis already exists.

Operation. After exposure of the lateral sinus, the next point to determine is the site and extent of the infected area (Fig. 244). On this will depend whether it will be necessary or not to tie the jugular vein in the neck.

The sinus is first exposed towards the jugular fossa until its surface appears normal for at least half an inch. It is wiser, however, always to expose the sinus as low down as possible. A strip of sterilized gauze is then pressed in between the bone and the outer wall of the sinus so as to obliterate its lumen at this spot. Instead of removing the bone from above downwards, the sinus may be exposed first at its lowest limit by chiselling directly through the tip of the mastoid process. In this way it can be obliterated by a strip of gauze before attacking the area of infection. The overlying bone is afterwards removed from below upwards until the thrombosed area is reached.

In removal of the bone from above downwards there is a certain risk of small particles of clot being dislodged into the circulation, or, if the sinus wall is injured, of hÆmorrhage taking place if the thrombus at this particular point does not completely occlude the sinus. If, however, the sinus be first exposed and obliterated at its lowest limit, these risks are greatly minimized. There is no special technique in removing the bone beyond that already given in the description of the complete mastoid operation.

The next step is to expose the lateral sinus behind the infected area and follow it backwards until the dura mater appears normal for at least three-quarters of an inch. If necessary, the skin incision must be prolonged still farther backwards, in order to permit of removal of the bone overlying the transverse sinus, which may, perhaps, have to be exposed even to the torcular Herophili.

In removing the bone overlying the infected thrombus, the gouge and chisel should be used rather than the bone forceps or burr. With the latter there is greater risk of dislodging particles of clot into the circulation, owing to pressure of the instrument on the sinus wall.

After the sinus has been exposed well beyond the region of the thrombus, the bone forceps may safely be used, especially in exposure of the transverse sinus; and this is a much more rapid method than removing the bone by means of the gouge and mallet. To prevent the inner blade of the forceps from nipping the sinus wall between it and the bone, the dura mater forming the outer wall of the sinus should be separated from the overlying bone by means of a dura mater separator. In the region of the infected area the sinus wall may be adherent to the bony wall as a result of the inflammatory adhesions, and, in addition, may be extremely friable and so easily torn through.

In exposure of the sinus two points should be remembered: firstly, that it is sometimes difficult to differentiate it from the dura mater covering the temporo-sphenoidal lobe above and the cerebellum below; and secondly, that the transverse sinus is a very much broader vessel than is imagined, being even half an inch in width. Not much force is required to obliterate its lumen, but care must be taken to pack the gauze evenly across its whole width.

After the sinus has been occluded above and below the area of infection, it should be incised with a small knife along its whole length between the obstructing plugs of gauze (Fig. 245). If there be bleeding, it may be due to the sinus being obliterated incompletely, or it may come from the superior petrosal sinus. To find out where the bleeding comes from, the finger should be pressed upon the sinus at its upper and lower limits, close to the obstructing plugs of gauze. If the bleeding stops, it shows that the sinus has not been obliterated completely; this can now be done by further plugging with gauze. If, in spite of this, bleeding still continues, it presumably comes from the petrosal sinus.

All clot and granulations are now rapidly curetted out and the lateral sinus plugged with gauze. After a moment the gauze is withdrawn and another small piece is pressed into the lateral sinus at the point of entrance of the petrosal sinus. After the bleeding has been arrested, the outer wall of the lateral sinus is excised by cutting it away with blunt-pointed scissors. The interior of the sinus is then inspected, special attention being given to the lower portion to see if its lining is normal. If this be not the case, even if there be no signs of thrombosis, it means that the surgeon has failed to get well below the infected area, and therefore the internal jugular vein must be ligatured. If, however, it be normal, the gauze plug already placed between the sinus wall and the overlying bone is left undisturbed.

If there be no bleeding from the sinus (excepting a slight amount from the blood contained within the isolated portion), the thrombus is curetted out and the inner surface of the sinus inspected. After excising the outer wall, search is made for the superior petrosal sinus, which presumably is thrombosed, although perhaps only by normal clot. To expose this tributary, which enters the lateral sinus at the point at which it turns downwards to form the sigmoid sinus, bone must be removed in front of the lateral sinus along the angle forming the roof and inner wall of the mastoid and antrum; that is, along the superior margin of the petrosal bone. If the inner surface of the lateral sinus in its neighbourhood be normal, nothing need be done. If, however, the sinus wall be infected, the petrosal sinus should be followed out, if possible, its outer wall being incised and the clot removed, bleeding being afterwards arrested by pressure.

As a final step, the gauze plugging which still obliterates the lumen of the sinus in its upper part is removed. If the sinus be normal at this point, free hÆmorrhage will occur; this is arrested at once by again introducing a strip of gauze between the sinus and the bone. Although during the earlier stages of the operation the inner lining of the posterior portion of the sinus may have seemed to be normal, yet it occasionally happens that hÆmorrhage does not at once occur on removing the plug of gauze; but after a moment or two a long smooth clot, gradually tapering at its end, may be shot out from the opening within the sinus, being followed by a gush of blood. The terminal portion of this clot is non-infective and of recent formation. Its appearance is always a matter of satisfaction, as it means that the sinus has been freely exposed and opened behind the infected area.

If on exposure of the sinus it be found that the clot extends so low down that it will be impossible to obliterate the sinus well below the infected area, the jugular vein should be ligatured at once before interfering further with the sinus from the mastoid wound.

Attempts to remove the clot from the jugular bulb by curetting out the sinus from above are only referred to to be condemned. The surgeon who believes in this method hopes that all the infected portion of the clot will be swept out by the flow of blood. It is not, however, always possible to introduce a curette into the jugular fossa, and if the clot extends beyond this region it cannot be curetted away completely. The result of the operation does not depend so much on the skill of the surgeon as on whether the terminal portion of the clot be infected or not. Recovery is most likely to take place if a non-infective clot already extends beyond the region of the curette and so obliterates by natural means the lumen of the vein below the point reached by the surgeon. If, on the other hand, free hÆmorrhage occurs as a result of the curetting, it means that the lumen of the vein has been restored, but there is no guarantee that all the clot has been completely removed. If any infective portion remains, a fatal result will almost certainly occur eventually as the result of pyÆmia.

LIGATURE OF THE JUGULAR VEIN

Indications. Unfortunately, opinion is not unanimous with regard to this matter. The chief arguments raised against ligature of the jugular vein are: (1) That it favours extension of the thrombus along the veins communicating with it, especially along the inferior petrosal and condyloid veins, which enter the jugular bulb. (2) That it in no way prevents the spread of infection along other paths, owing to the freedom with which its tributaries communicate with one another. (3) As a result of obstruction in the circulation, acute inflammation of the cerebellum may take place.

Since the jugular vein should only be ligatured if the symptoms point to the onset of a general infection of the circulation and if it be found impossible at the time of operation to obliterate the sinus below the infected thrombus, and since this vein is the chief route by which this infection takes place, it seems a matter of common sense that it should be ligatured. At the same time, as many as possible of its tributaries above the point of ligature should also be ligatured well beyond the point at which they may be thrombosed.

Although extension of the infection may take place along other veins after ligature of the jugular vein, it is impossible to say whether the result is post or propter hoc. Against ligature, statistics have been quoted to show that in a series of cases in which the jugular vein has not been tied the percentage of recoveries is just as high as in those in which it had been ligatured. This argument is not quite sound, because there is no doubt that in the cases in which ligature of the jugular vein is justified the chances of recovery, owing to the extension of the thrombus downwards, must be less than in the less serious cases in which it is admittedly unnecessary to tie the vein. It is also impossible to say how many cases would otherwise have ended fatally if ligature had not been performed.

In the majority of cases the vein is ligatured after exploration of the lateral sinus. In a few cases, however, the symptoms warrant it being performed as a primary step of the operation, even before the mastoid process has been opened.

After exposure of the lateral sinus. (i) If the clot extends so low down that it is impossible to obliterate the lumen of the sinus below its lower limit.

(ii) If there be thrombosis of the bulb of the jugular vein. This condition is sometimes difficult to diagnose. There may be no symptoms excepting, perhaps, rigors occurring during the course of chronic middle-ear suppuration, as even the lower portion of the sinus may be quite normal in appearance owing to the clot being limited entirely to the jugular bulb. The probability of the diagnosis being correct is strengthened by the presence of granulations or carious bone on the floor of the tympanic cavity. It is better to risk tying a normal vein than to fail to tie one already infected.

(iii) If the sinus was obliterated above the jugular bulb at the primary operation and rigors occur subsequently, showing that the sinus is infected still lower down.

Before exposure of the lateral sinus. (i) If there be thrombosis of the jugular vein. In addition to the ordinary signs of lateral sinus thrombosis, there may also be infiltration of the tissues, or tenderness along the anterior border of the sterno-mastoid muscle. The prevalent idea that a thrombosed jugular vein can be felt on palpation as a hard cord extending down the neck is erroneous. If anything be felt it is probably some enlarged cervical glands lying along the line of the vein. In any case it is bad practice to palpate the internal jugular, as by doing so there is considerable risk of dislodging particles of the septic clot.

(ii) If, as a result of septic infection, the general condition of the patient be so serious that a prolonged operation seems unjustifiable. In such cases, the lateral sinus is rapidly exposed and incised after tying the internal jugular, its contents are curetted out and the wound cavity lightly plugged; the completion of the operation, consisting of the opening up of the mastoid cells and antrum, and possibly also exploration of the intracranial cavity, may be performed next day or later.

(iii) If it be doubtful whether septic thrombosis of the sinus has already occurred, it is justifiable in certain cases merely to expose the sinus freely and not to open it (see p. 440). If rigors subsequently occur in these cases and it becomes evident that the sinus has become infected after all, then it is wiser to tie the jugular vein as a primary step of the operation before opening up the sinus itself.

The writer’s reason for doing so is, that at the second operation he has always found the clot to be extensive, or, at any rate, to be situated so low down as to prevent the sinus being obliterated below the infected area.

Operation. Formerly it was considered sufficient to divide the vein between two ligatures and to leave it in situ. Now, however, the upper portion of the vein is brought out through the wound in the neck after this has been done.

The patient lies in the recumbent position with the affected side close to the edge of the table. The head and shoulders should rest on a hard pillow in such a fashion that the neck is slightly extended, the chin being drawn upwards and the head turned a little to the opposite side so that the anterior border of the sterno-mastoid muscle can be clearly defined throughout its whole length. The surgeon stands at the side to be operated on. The neck is carefully cleansed, but in doing so care should be taken not to rub the neck too violently, nor should any attempt be made to palpate the line of the jugular vein in the hope of feeling it. There is no object in doing so, and if it is thrombosed a portion of the clot may be dislodged.

An incision, at least three inches in length, is made along the anterior border of the sterno-mastoid muscle, the mid-point of the incision corresponding to about the level of the cricoid cartilage. On cutting through the skin and platysma some small veins may be met with: they should be clamped with forceps and divided. If, however, the anterior jugular vein be exposed, it should be drawn to one side, if possible, and not divided. The anterior border of the sterno-mastoid muscle is clearly defined, until the upper border of the omo-hyoid muscle is reached (Fig. 246). Its edge is then drawn slightly outwards by means of a retractor and separated from the underlying deep fascia. Beneath this fascia is the carotid sheath, which encloses not only the carotid artery but the internal jugular vein and the vagus nerve. The vein is external and somewhat superficial to the artery, and the vagus nerve lies behind. A vein of varying size will be seen crossing obliquely downwards and outwards to pierce the deep fascia at a level corresponding to the cornua of the hyoid bone; this is the common facial vein about to enter the internal jugular (Fig. 247). If the surgeon has not had much experience and has difficulty in finding the jugular vein, a certain method of doing so is to find the facial vein and then follow it down until it enters the jugular. The carotid sheath should be opened about this point, and the position of the vein ascertained by feeling the pulsations of the carotid artery. The sheath of fascia covering the jugular vein is picked up with a pair of fine forceps and cut through with a sharp scalpel, which should be inclined obliquely outwards so that the flat of the knife is held towards the vessel. Any enlarged lymphatic glands lying over the vein must be removed.

When the vein has been identified, a blunt dissector is passed between its outer wall and the sheath, so as to separate the two. The sheath is incised upwards and downwards until the vein is freely exposed. If the vein be patent, it will be of a bluish colour, expanding and diminishing in volume with each act of respiration. If it be thrombosed, there is usually accompanying periphlebitis which may make the separation of the sheath from the vein and the surrounding tissues difficult. If there be no periphlebitis, the thrombosed portion may be purplish, or, if the clot be of long standing and breaking down, more of a yellowish colour; the vein stands out as a cord and does not pulsate. If the thrombus be limited to the portion above the entrance of the common facial vein, the upper portion of the jugular may be small and collapsed, only becoming full and pulsating below the point at which the facial joins it.

The next step in the operation is to get well below the point at which the jugular is thrombosed. If the thrombus be practically limited to the jugular fossa the vein may be ligatured above the common facial; if not, as low down the neck as possible. In ligaturing the vein low down in the neck, the skin incision must be extended downwards, and as the lower portion of the neck is reached, the omo-hyoid will have to be pulled aside. The probe should be passed all round the vein so as to make certain that it is freed from its sheath, and especially that it is separated from the vagus nerve which lies behind it.

An aneurysm needle threaded with silk is now passed around the vein from within outwards. The loop of silk is cut so as to form two ligatures, and the aneurysm needle then withdrawn; the lower ligature is first tied, its ends being cut short. The upper ligature is then tied a short distance above it, but in this case the ends are left long. The vein is raised from its bed by slight traction on this ligature and is cut across between the two, the lower portion being allowed to sink back into the wound. The upper portion is then carefully separated for some distance upwards. Lying behind the vein may be seen the vagus nerve (Fig. 248). Any tributaries are clamped between two forceps, cut across, and ligatured, the upper end of the vein being brought out into the upper angle of the wound. Care must be taken that enough of the vein is dissected out to allow of this being done, especially if the ligature is applied above the level of the common facial; in this case the facial need not be tied.

If there be no periphlebitis, inflammation of the soft tissues, or thrombosis of the vein itself in the neck, the wound may be closed by means of silkworm-gut sutures, excepting at its upper angle through which the open end of the jugular vein projects. If, however, the vein be thrombosed, and especially if there be periphlebitis, the wound should be left open, except perhaps at its lower angle, and should be lightly packed with gauze, as in these cases cellulitis of the neck may afterwards occur.

After completion of the operation in the neck the surgeon turns to the mastoid process. If the ligature of the vein has been the primary step, the mastoid operation is now performed and the lateral sinus is freely exposed for a considerable distance behind the thrombus. If, however, the mastoid operation has been the first stage, and the jugular has been tied as soon as exposure of the sinus showed it to be thrombosed, the operation on the mastoid is now completed and the sinus opened as already described (see p. 444). The next step is to incise the sinus freely from above downwards towards the jugular fossa and curette out the thrombus.

If there be considerable hÆmorrhage, it means that the thrombus is probably parietal and situated within the jugular bulb, the bleeding presumably coming from the inferior petrosal sinus or other tributaries which enter the bulb or upper portion of the jugular vein. If the bleeding be excessive, the sinus is plugged after a moment or two, by inserting a piece of gauze into its lumen towards the jugular bulb.

In this case the portion of the vein brought into the neck is usually also filled with blood. After isolating it from the deeper tissues by packing strips of gauze round it, the vein is deliberately opened just above the ligature. The bleeding usually stops after a moment or two, but if it cannot be controlled, the lumen of the vein must again be closed by a ligature, the end of the vein being allowed to project on to the neck.

If there be no bleeding from the lower portion of the lateral sinus and jugular bulb, it means that the vessel is completely thrombosed at this point. The clot should now be removed by curetting through the sinus from above downwards towards the jugular bulb, and also from below upwards through the open end of the jugular vein.

The venous channel is afterwards syringed through from above downwards. To do this, a piece of rubber tubing is inserted into the opening in the lateral sinus and some warm saline solution is injected through it with a syringe. If the clot be not firmly adherent it can usually be washed out through the opening in the vein. No force should be used. If gentle syringing be not sufficient to expel the clot, the attempt must be given up. The chief objection against syringing is the possibility of particles of the septic thrombus being forced into the veins communicating with the jugular bulb. A small drainage tube is inserted within the sinus.

In order to keep the lumen of the vein in the neck open, it should be stitched to the edge of the wound surface by several catgut sutures (Fig. 250). If the bleeding necessitated plugging of the lower end of the sinus and retention of a ligature on the vein in the first instance, syringing should be postponed until the first dressing; the portion of the vein left protruding through the skin wound in the neck is then cut across, and the edge of the vein sutured to the margin of the wound under cocaine.

The mastoid cavity is lightly plugged with gauze and a dry dressing applied. The wound in the neck is similarly treated.

After-treatment and progress of the case. There is frequently considerable shock after the operation, especially if exposure of the jugular bulb has been undertaken, partly owing to the duration of the operation and to hÆmorrhage. If the patient be very collapsed, a continuous saline injection, to which some brandy may be added, may be given per rectum according to Moynihan’s method. After the primary shock has passed off, the immediate result is usually satisfactory.

If the jugular vein has not been ligatured, the first dressing should be performed within forty-eight hours, the gauze packing being removed, the wound syringed out, and afterwards repacked. The plugs of gauze, which were pressed in between the outer wall of the sinus and the overlying bone in order to obliterate the lumen of the latter, should not be interfered with for at least six days. If the case progresses favourably, the temperature becomes normal within a day or two, the patient feels well, and the wound assumes a healthy appearance. If, on removal of the gauze plugging, hÆmorrhage takes place, then the plugging must be renewed and not touched again for three or four days. After it is possible to remove these plugs, the wound is treated as has already been described in Schwartze’s operation or in the complete operation in which the posterior wound was left open.

If the jugular vein has been ligatured, the sinus and vein should be syringed through daily, and this should only be stopped after all secretion has ceased, usually a matter of a week or ten days.

When the sinus, jugular bulb, and vein have been exposed throughout their length the wound is treated as an ordinary surgical one, being packed until it granulates up from the bottom (vide infra).

Apart from intracranial and pyÆmic complications, the progress of the case may be delayed owing to the enfeebled and septic condition of the patient, and also from the occurrence of abscesses in the neck, or region of the mastoid itself. These abscesses are the result of septic thrombosis occurring in some tiny vessel. The first sign of their occurrence is an attack of pyrexia, shortly followed by a painful swelling at the affected spot. Any collection of pus should be drained at once. Although it is quite good practice to close the incision in the neck in a clean case, yet there must be no hesitation to open it up on the slightest sign of it becoming septic.

The case may appear to progress favourably for the first week or ten days, and then an intermittent and increasing pyrexia may occur for no obvious reason. This is usually due to extension of the infection along the petrosal sinuses, or perhaps along the transverse sinus.

Symptoms of involvement of the cavernous sinus may arise, perhaps even with formation of a peri-orbital abscess; or, on the other hand, the patient may gradually sink in consequence of septic toxÆmia; or the end may come more suddenly with the onset of basal meningitis. Unfortunately, these cases are almost hopeless from the first, as very little can be done from a surgical point of view owing to the fact that they are not seen soon enough.

In thrombosis of the cavernous sinus the only hope of recovery lies in its exposure and incision of its wall. The sinus may be approached by tracking forwards the superior petrosal sinus—a matter of considerable difficulty, and seldom justifiable. Recently Charles Ballance has suggested the adoption of the Hartley-Krause route for extirpation of the Gasserian ganglion, and says he has found the operation easy and effectual. If pus be evacuated from the sinus he considers it advisable to adopt the recommendation of Voss, who cuts away the zygoma and removes more bone from the basal aspect of the skull so as to get direct drainage (Allbutt and Rolleston’s System of Medicine, 1908, vol. iv, Part ii, p. 495).

EXPOSURE OF THE JUGULAR BULB

This may be performed either by following the sinus downwards or through the floor of the auditory canal and tympanic cavity. The former method was first described by Grunert (Archiv fÜr Ohrenheilkunde, 1902, vol. liii, p. 287); the latter by Piffl (Archiv fÜr Ohrenheilkunde, 1903, vol. lviii, p. 76).

Indications. The object of the operation is to remove the septic clot situated within the jugular bulb in the hope of preventing extension of the infection along the veins leading into it, more especially the inferior petrosal sinus. This indeed has been known to occur even after the lateral sinus has been curetted out, the jugular vein ligatured, and the venous channel syringed through.

Grunert’s operation. After free opening of the mastoid process and exposure of the outer wall of the lateral sinus, the skin incision is extended downwards beyond the tip of the mastoid. The soft tissues are then separated from the bone forwards and backwards so as to expose completely not only the mastoid process, but also the digastric fossa and base of the skull immediately behind it, up to the outer bony margin of the jugular foramen. Unless care is taken, the forcible traction forwards of the soft tissues necessary to expose the field of operation may injure or tear the facial nerve as it emerges from the stylo-mastoid foramen.

The tip of the mastoid process is removed first. The lateral sinus is then freely exposed to its lowest possible limit by removing the overlying bone. In doing this it must be remembered that the sinus becomes horizontal just before it ends in the jugular fossa, so that at this point the skull forms its floor instead of its outer wall.

After having exposed the sinus as freely as possible, the ‘bridge’ of bone separating it from the outer wall of the jugular foramen is removed in small pieces by nipping it away with narrow biting forceps until the jugular bulb is exposed from its outer surface. The facial nerve should not be injured, as it lies in front and external to the portion of the bone to be removed.

In performing the later stages of the operation, the patient’s head should be turned well over to the opposite side in order to get a good view of the parts lying behind and beneath the mastoid process; and in tracking the sinus downwards, the probe should be used carefully in order to try and define the exact position of the jugular fossa.

Piffl’s operation. Owing to the anatomical difficulty of reaching the jugular bulb by following the sigmoid sinus downwards, especially in those cases in which the sinus lies far forwards and in which, at the same time, there is a very well-developed jugular fossa, Piffl recommends exposure of the jugular bulb from above through the auditory canal. The object of this method is to prevent injury to the facial nerve, which he states is almost certain to occur in Grunert’s operation, if carried out in cases such as those just mentioned.

After the complete mastoid operation has been performed, the skin incision is extended downwards and forwards in order that the soft tissues may be freed from the floor and anterior surface of the bony portion of the auditory canal as far forward as the Glaserian fissure. The soft tissues are pulled forward with a blunt hook to give sufficient room. The lower portion of the tip of the mastoid is removed by means of the gouge, as far as can be done without injuring the facial nerve, which in this operation is pulled backwards with the soft tissues at the posterior inferior margin of the wound. The lower bony margin of the auditory canal, now freely exposed, is removed by means of a pair of fine biting forceps until the floor of the tympanic cavity is reached. If there be not sufficient room, the bone may be clipped away as far as the styloid process, which also may be removed by bone-forceps after the muscles attached to it have been dissected off.

In freeing the styloid process, its posterior surface must be approached with caution for fear of injuring the facial nerve, which here lies in close connexion with it. In the front of the wound the capsule of the temporo-maxillary joint may be exposed, but must not be interfered with.

After removal of the styloid process, the uppermost portion of the external jugular vein should be seen emerging from the jugular fossa. This is followed upwards by careful removal of the bone between it and the floor of the auditory canal and tympanic cavity, until the jugular bulb is brought into view. This part of the operation must be proceeded with very cautiously, the bone being nibbled away in small fragments with gouge forceps which are of sufficient strength to nip through the bone without having to wrench it away. The amount of bone to be removed and the difficulty of the operation depend largely on the anatomical condition found.

Whether Grunert’s or Piffl’s operation has been employed, the operation may be completed either by incising the outer wall of the sinus and jugular bulb, then curetting out the thrombus, and finally washing through the lower portion of the vein from above downwards, or by the more radical method of also exposing the upper portion of the jugular vein throughout its whole length. To do this the post-aural incision is continued downwards until it joins the one previously made in the neck. To obtain room, the neck must be somewhat extended and the jaw pulled well forward and the sterno-mastoid muscle backwards. The jugular vein is then dissected upwards towards the bulb.

The nearer the jugular fossa is approached the deeper and more difficult becomes the exposure of the vein. Passing in front of it may be found the stylo-pharyngeal, stylo-hyoid, and digastric muscles. In Grunert’s operation they need not be cut through as the vein will lie posterior to them. In Piffl’s operation these muscles probably have been already reflected forward, after removal of the styloid process.

Particular care must be taken not to injure the nerve trunks, which are in such close relationship with the vein. Lying immediately behind the vein is the vagus nerve; the spinal accessory passes downwards and outwards behind it, and the glosso-pharyngeal and hypoglossal nerves forwards between the vein and the internal carotid artery.

After the vein, the jugular bulb, and the sigmoid sinus have been exposed throughout their course, their outer wall is cut through with a pair of blunt-pointed scissors along its whole length, so as to convert the venous canal into an open gutter. The thrombus is then curetted out and the dissected portion of the jugular vein cut off as high up as possible. Any bleeding from the inferior petrosal sinus or condyloid veins, which may not be thrombosed, should be arrested by direct pressure of a strip of gauze over the bleeding points. The wound cavity is then washed out with a weak biniodide solution and dried.

The lower portion of the incision in the neck may be closed with sutures and a small drainage tube inserted at its lower angle. The upper portion of the wound, now directly continuous with that of the mastoid cavity, is left open and packed lightly with gauze, which is inserted into the remains of the venous channel.

Comparison of operations for lateral sinus thrombosis. Except when the thrombus is limited to the upper part of the sigmoid sinus, it is undoubtedly wiser to tie the jugular vein than to be content with curetting out the clot after obstructing the sinus above and below by means of gauze plugs. Exposure of the jugular bulb is so difficult an operation and requires so much time, especially if the whole length of the upper portion of the jugular vein is also dissected out, that it is seldom advisable to perform it; nor will it often be justifiable owing to the condition of the patient, who is seldom strong enough to undergo such a prolonged operation. The records of this particular operation are so few that it is impossible as yet to determine its value.

If the sinus be exposed as low down as possible, and the jugular vein dissected out and brought out into the neck, and the venous channel afterwards syringed through, the chances of recovery should be almost as good as in the case of free exposure of the jugular bulb.

If the inferior petrosal sinus be already infected before the operation, it does not matter whether the operation performed is that of syringing through the jugular bulb or freely exposing it, as in either case the inferior petrosal sinus cannot be followed out.

Curetting of the lower portion of the sinus without previous ligature of the jugular vein should never be done.

Difficulties and dangers of the operation. The chief difficulty in these operations is anatomical; the chief danger is hÆmorrhage.

If the hÆmorrhage be due to accidental tearing of the wall of the sinus in the earlier part of the operation, and if it be impossible to obliterate the sinus below this point by pressing in gauze between its wall and the underlying bone, then the jugular vein should be tied before anything else is done.

Extreme vascularity of the bone is not unusual after ligature of the jugular vein. In these cases the surgeon must rely on the cleverness of the assistants in keeping the field of operation clear by careful swabbing.

In exposure of the jugular vein there may be difficulty in finding the vessel, especially if the cervical glands are enlarged, or if there be matting together of the tissues in consequence of periphlebitis or cellulitis. In these cases the best plan is to identify the common facial vein and then trace it down to its entrance into the jugular vein.

With regard to the sinus, the chief danger is injury of its inner wall whilst curetting out its contents: this may afterwards give rise to meningitis or a cerebellar abscess. Accidental pricking of a non-thrombosed jugular vein may allow of entry of air into the vein and so cause death: this is a catastrophe I have not yet met with. Also, if the operator be careless or inexperienced, he may injure the carotid artery or vagus nerve; in the former case the only thing to do is to ligature the artery above and below the wound.

Complications. The chief intracranial complications are meningitis and cerebellar abscess; the former usually from extension of the septic thrombosis along the petrosal sinuses. If, at the time of operation, it be doubtful whether intracranial suppuration already exists or not, the surgeon should content himself with removing the septic thrombus from the sinus and await further symptoms. At the time of the operation, however, sufficient bone should be removed to expose the dura mater over the cerebellum. If, in addition to the clinical symptoms, the appearance of the dura mater, the increased intracranial tension, and the absence of palpation suggest the presence of an abscess, the cerebellum should then be exposed and explored (see p. 467). Before doing this, the wound should be made as aseptic as possible and a fresh set of sterilized instruments used.

The complications resulting from general septic infection are pyÆmia and septicÆmia.

Prognosis. The prognosis depends entirely on whether the septic focus can be completely removed or not. Failure to do this is frequently due to the operation not having been sufficiently extensive. It is a matter of experience that if a second operation has to be performed recovery seldom takes place. For this reason the first operation must be thorough.

If such cases could be operated on in the earliest stage whilst the infective thrombus was still limited, without doubt a higher percentage of recoveries would be obtained. Unfortunately, the surgeon may not be summoned until too late, owing to the seriousness of the condition not having been realized.

In any individual case it is impossible to tell for the first few days after the operation what the ultimate result will be. Without operation a fatal termination is practically certain. As a result of operation about one-third of the cases may be expected to recover.

CHAPTER X
OPERATIONS FOR INTRACRANIAL ABSCESS
OF OTITIC ORIGIN

An intracranial abscess, the result of disease of the temporal bone, is usually situated close to the surface of the brain, and is in close relationship with the diseased area of bone through which the infection has taken place. The actual track of the infection can frequently be traced through the bone to the dura mater and brain substance itself; sometimes, indeed, a fistula is found to pass through the bone and to communicate with the intracranial abscess. On the other hand, though rarely, the surface of the bone to all appearances is normal and there are no adhesions between it and the dura mater and underlying brain substance, and the abscess may be situated deeply within the brain.

With regard to the comparative frequency of temporo-sphenoidal and cerebellar abscess, in 100 cases collected from the records of the London Hospital the writer found that in children under ten years of age temporo-sphenoidal abscess occurred in 87% and cerebellar only in 13%, whereas in adults cerebral abscess occurred in 65% and cerebellar in 35%; and that a cerebral and cerebellar abscess occurred together only in 5% of the cases.

These statistics are practically the same as KÖrner’s (Die otitischen Erkrankungen des Hirns, der HirnhÄute und der Blutleiter). Ballance, on the other hand, considers cerebellar abscess a more frequent occurrence than temporo-sphenoidal.

Multiple abscesses may be met with, usually the result of pyÆmia.

Indications. An intracranial abscess must always be opened and drained.

Indications pointing to such a condition are persistent headache, purposeless vomiting, a slow pulse, a subnormal temperature, and optic neuritis. With this there is usually some change in the mental condition, especially in the case of a temporo-sphenoidal abscess. In the early stages there may be attacks of simple forgetfulness or mental aberration, or, on the other hand, that of extreme mental excitement. Owing to the intracranial pressure caused by the increase in size of the abscess, the mental state becomes impaired and the condition known as slow cerebration or the ‘dream state’ may be observed.

It must, however, not be forgotten that the same clinical picture may be produced by other conditions, such as an intracranial tumour: in the case of a middle-ear suppuration, however, an intracranial abscess may be diagnosed unless this can otherwise be excluded.

Before operation is decided on, the site of the lesion must be determined. This can only be done if certain localizing symptoms are present.

In a temporo-sphenoidal abscess, if the cortical region be affected, there may be paralysis or paresis of the opposite side, beginning with the face and then spreading to the arm and leg; or in the opposite order if the internal capsule be involved.

If the left temporo-sphenoidal lobe be the site of the lesion, aphasia may be met with, and if the abscess extends backwards, word-blindness may occur. If the centre of hearing be affected there may be complete deafness of the opposite side owing to its destruction; or tinnitus or hyperacusis if the centre be only irritated by the proximity of the abscess; or if the anterior extremity be involved anosmia or parosmia may be noticed. Another important sign, occurring in conjunction with the above symptoms, is a fixed pupil on the affected side.

In a cerebellar abscess the symptoms are less marked, or may even be absent, so that the abscess may remain undiagnosed during life and only be discovered at the autopsy, which may perhaps have been performed on account of the sudden and unexpected death of the patient from rupture of the abscess itself. In walking, in addition to a peculiar staggering gait, there is a tendency for the patient to direct his course gradually towards the affected side. Lateral nystagmus, if present, is usually directed towards the affected side and has to be differentiated from that due to internal-ear disease. If a cerebellar abscess be associated with a labyrinthine suppuration and the latter is explored by operation, the nystagmus will still remain directed to the affected side. If, however, no cerebellar abscess be present the labyrinthine operation will be followed by nystagmus strongly directed to the opposite side. Optic neuritis and vomiting usually are more severe than in temporo-sphenoidal abscess. Headache, if present, may be referred to the occipital region, and there may also be slight retraction of the neck or pain behind the mastoid region as a result of localized and early meningitis of the posterior fossa. If the abscess be very large, there may be paresis or paralysis of the facial nerve and perhaps also of the upper extremity. The deep reflexes may also be altered, the knee-jerk being frequently absent on the affected side. The patient in the late stage usually lies curled up in bed on the side opposite to the lesion, with the knees flexed.

Methods of operation. Two methods may be employed:—

1. Trephining directly over the area of the abscess (rarely necessary).

2. First performing the mastoid operation and then following out the route of infection (usual method).

In the case of middle-ear suppuration, trephining has practically been abandoned, and rightly so, since it has become recognized that the intracranial abscess is due to direct extension of the pyogenic infection from the middle-ear and mastoid cavities.

The only circumstances in which trephining may be advised are—(1) If the diagnosis be certain and the operator has no experience of aural surgery. In a case of emergency he is wiser, perhaps, to trephine and drain the abscess, leaving the mastoid to be dealt with afterwards by someone competent to do so. (2) If, after performing the mastoid operation, the situation of the abscess be doubtful. In order to diminish the risk of infection of the brain by an exploratory puncture which may prove negative, the bone may be trephined a little beyond the mastoid wound, either above or behind, according as a temporo-sphenoidal or cerebellar abscess is suspected. If, however, it be considered advisable to make a fresh opening in the bone beyond the septic wound cavity, the aural surgeon will probably prefer to do so by means of the gouge and bone-forceps, to which he is more accustomed.

Trephining has also been advised if the patient is so ill that a prolonged operation is impossible; or if there is cessation of respiration during the operation itself, which may occur in a cerebellar abscess as a result of pressure on the medullary respiratory centres. To those accustomed to perform the mastoid operation, the opening of this cavity and the necessary removal of bone can be done more rapidly by the gouge or bone-forceps than by the trephine.

For whatever reason trephining is done, it is afterwards essential to perform the mastoid operation and to remove the primary focus of the disease, otherwise one of the fundamental principles of surgery will be neglected.

Operation. The preliminary preparation of the patient is the same as for the mastoid operation, only the head should be shaved over a wider area. The exposure of the field of operation is the same whether the brain is explored through a trephine opening or from an extension of the mastoid operation.

In the case of the temporo-sphenoidal lobe, it is necessary to extend the incision behind the auricle vertically upwards for an inch or more (Fig. 252); whereas if the cerebellum has to be explored, an incision is carried backwards at right angles to the post-aural incision, just below its mid-point (Fig. 253). In the former case, on reflecting the soft tissues from the underlying bone, the squamous portion of the temporal bone, immediately above the zygomatic ridge, will be exposed; in the latter, the base of the skull behind and below the mastoid process and lateral sinus will be laid bare.

1. Trephining. The trephine used should be three-quarters of an inch to one inch in diameter according as the patient is a child or an adult. Either the hand trephine or Macewen’s improved pattern mounted with a guard may be used. If available, the trephine may be worked by a motor, but in this case it should be remembered that the bone will be pierced more quickly than by the hand instrument.

Trephining for a temporo-sphenoidal abscess. The object of the operation is to expose the lowest portion of the middle fossa just above the roof of the antrum and tympanic cavity. The trephine, therefore, should be placed so that it is situated just above the suprameatal spine, its lowest margin being slightly above the zygomatic ridge (Fig. 251). After the disk of bone has been removed the exploration of the abscess is then carried out.

Trephining for a cerebellar abscess. The point at which the bone is trephined must be behind and below the curve formed by the transverse and sigmoid portion of the lateral sinus; that is, behind the mastoid process and below Reid’s base-line.

If the mastoid operation has not been performed, the centre pin of the trephine should be placed at a point 1¼ to 1½ inches behind the centre of the external auditory meatus, and an inch below Reid’s base-line (Fig. 251). If, however, the mastoid has already been opened and the lateral sinus exposed, the trephine should be placed so that its anterior border is just behind the sinus and its upper border well below Reid’s base-line.

2. After performing the mastoid operation. If this has been done already, the wound is reopened, and cleansed by filling it with hydrogen peroxide. After gently curetting away any granulations the wound cavity is irrigated and then packed in order to dry it. Under good illumination, careful inspection is made to see if a fistula or a tract of diseased bone extends in any direction. Whether the middle or posterior fossa should first be explored depends not only on the clinical symptoms but also on the condition found on opening the mastoid cavity.

Opening of a temporo-sphenoidal abscess. A temporo-sphenoidal abscess may be explored either through its lowest point, that is, through the roof of the antrum and floor of the middle fossa, or through its outer wall just above the zygomatic ridge. To obtain a view of the roof of the antrum and mastoid cavities, the head of the patient should lie almost flat on the operating table and be turned well over to the opposite side. The bony roof of the antrum and mastoid is removed by means of the gouge and mallet, and so expose the dura mater covering the floor of the middle fossa (Fig. 252). If a fistula communicates with the antrum cavity and the middle fossa, the bone surrounding it is first attacked. In removing the bone, it must be remembered that the tegmen tympani is exceedingly thin, and unless care is taken pieces of bone may be pressed inwards on to the overlying dura mater. Sufficient bone should be removed to determine whether the dura mater is normal or not. To do this it may be necessary to chisel away the tegmen tympani outwards until the squamous portion of the temporal bone is reached, after which a pair of bone forceps may be used until a sufficient opening is obtained.

The condition found on examination of the dura mater varies. In many cases it is congested or covered with granulations at the site of the infection, and usually it is adherent to the underlying bone. At other times it seems normal.

Increase of the intracranial pressure, as shown by the bulging outwards of the dura mater, and absence of pulsation are suggestive of an abscess. These signs, however, are not conclusive, as on the one hand increased intracranial pressure may be due to other causes and on the other it is quite possible to have pulsation if the abscess be small and deeply placed.

If an extra-dural abscess be present, the intracranial cavity should not be explored at once unless this is absolutely necessary, but this step of the operation should be delayed for at least twenty-four hours. If, however, immediate operation be necessary, special precautions must be taken to render the part as aseptic as possible, and a fine layer of gauze should be packed between the margin of the bone and the dura mater in order to prevent further infection of the brain or meninges. In an uncomplicated case only sufficient bone should be removed to permit of the insertion of a large drainage tube; that is, the dura mater should not be exposed over a larger area than the size of a shilling.

If there be disease of the tegmen tympani and the symptoms point to a temporo-sphenoidal abscess, the brain should be explored through this opening in the bone (Fig. 252), as the abscess is thus not only drained through its most dependent part, but also through its stalk.

If, however, the diagnosis be doubtful, the temporo-sphenoidal lobe may be explored through a fresh opening, just above the tegmen tympani. This will diminish the risk of septic infection from the mastoid cavity. After the dura mater has been exposed sufficiently a small incision is made in it, taking care to avoid wounding any of the vessels. With a pair of forceps the cut edge of the dura mater is drawn outwards and the incision is prolonged in each direction with a pair of blunt-pointed scissors. Similarly, the dura mater is cut through at right angles to the primary incision, so that four small flaps are made and turned back so as to expose the outer surface of the brain.

As a rule the dura mater, arachnoid, and pia mater are fused together by inflammatory adhesions, so that from a practical point of view they need hardly be considered as separate structures. Similarly, at the site of infection, the point of the so-called stalk of the abscess, the cerebral membranes are adherent to the underlying brain, especially if there has been any localized meningitis. For this reason it is sometimes necessary to peel away the dura mater from the brain, in order to expose the latter.

As a rule, very little fluid escapes: if present in considerable quantity, and if it escapes from between the dura mater and brain, it is an unfavourable sign, as it generally signifies early meningitis.

If meningitis be present, purulent lymph or secretion may be seen on the surface of the brain, either localized or spreading from the site of the infection.

If the intracranial pressure be great, the brain will bulge through the opening in the dura mater. If the abscess be very large and situated superficially, the thin layer of brain substance forming its outer wall may rupture as soon as an opening has been made in the dura mater. Sometimes, indeed, the pus may be seen to ooze through an opening in the dura mater, which may be found to communicate with the abscess cavity.

The next step is to open the abscess. Formerly a trocar and canula were used. This method is no longer in favour for the following reasons:—If the wall of the abscess cavity be very thick, it may not be pierced; secondly, the trocar may pass through the abscess cavity and enter the brain substance beyond without draining it; and thirdly, even if the trocar enters the abscess cavity the pus may be so thick as to plug its lumen. For these reasons a fine pair of Lister’s sinus-forceps or a narrow-bladed bistoury is recommended. In the ordinary case Lister’s forceps can be used.

The direction in which the brain is explored depends upon the point at which this is done. Thus, if the procedure be carried out through the tegmen tympani, the brain is explored in an upward direction. The forceps are made to pierce the brain for about an inch; the blades are then slightly dilated and the forceps partly withdrawn. If a large abscess exists, the cavity is usually opened at once and pus flows out along the track of the forceps. If the abscess be small and deeply placed, its cavity may not be entered on the first thrust of the forceps. In this case they are closed and withdrawn. The brain is then explored by thrusting the forceps first upwards and forwards, then upwards and backwards, and finally upwards and inwards; in the latter case it is unwise to pierce the brain for more than an inch and a quarter for fear of entering the lateral ventricle.

If the brain be explored through the outer wall of the temporo-sphenoidal lobe, the first direction in which this is carried out is directly inwards. If this be not successful, the brain is further explored in a direction forwards, upwards, or backwards, the exploratory instrument at the same time pointing slightly inwards.

If exploration proves negative, it may also be necessary to explore the cerebellum. If, however, the surgeon be still convinced that a temporo-sphenoidal abscess exists, he may next pierce the brain with the bistoury, in case the forceps has failed to enter the abscess cavity, perhaps owing to its walls being very thick. If all efforts fail to find the abscess, the little finger may be inserted into the brain itself to see if the resistant wall of an abscess can be felt. This procedure, however, should be avoided if possible, as by doing so it causes destruction of a certain amount of brain tissue.

If an abscess be opened a varying quantity of pus escapes, usually evil smelling. In the more chronic cases it is thick and greenish; in the acute cases it may contain shreds of necrosed brain tissue or be intermixed with bubbles of gas. Sometimes there is also an escape of turbid cerebro-spinal fluid, which if excessive is suggestive either that the lateral ventricle has been opened inadvertently or that the abscess has already burst into it. In these cases the patient is usually comatose or in the state of muttering delirium at the time of the operation.

After the abscess has been opened, the forceps or bistoury should be retained in position until the pus has drained away. A large tube is then pushed into the abscess cavity along the line of the forceps or bistoury. It is only permissible to withdraw the instrument with which the abscess has been opened after the end of the tube is well within the cavity. The outer end of the tube should be flush with the surface of the wound. To prevent it slipping too far into the brain, it may be anchored to the edge of the skin wound by a silkworm-gut suture. If the abscess be drained through the tegmen tympani, it will be difficult to bring the tube out into the wound without kinking it. For this reason I prefer to incise the brain substance slightly outwards after the abscess cavity has been reached, so that a tube can be inserted obliquely upwards and inwards at a point corresponding to the angle between the tegmen tympani and the squamous portion of the temporal bone. If the exploratory puncture has been made above the tegmen tympani and an abscess discovered, the question arises whether another drainage tube should not also be inserted into the brain through an opening in the roof of the antrum so as to drain the abscess from below. This, however, I do not think necessary.

In addition to the rubber tube, many varieties of drainage tubes have been suggested, such as decalcified chicken bone, as originally used by Macewen, and glass or silver tubes; the object of the latter being to resist the pressure of the brain, which may compress a rubber tube. The rubber tube is the simplest form of drainage, and if sufficiently thick it should be employed. To make more certain of free drainage, some surgeons use two tubes placed side by side. I think, however, one large tube (half an inch in diameter) is better than two small ones.

Irrigation of the abscess cavity is still a matter of opinion. If the abscess be small and circumscribed, the best method is to open it with as little disturbance as possible to the surrounding parts, insert a large drainage tube, and to do nothing further.

If, however, the abscess be large and irregular in shape, so that the drainage is not free, and especially if it be very septic and contains necrosed brain tissue, irrigation is justifiable if gently carried out. The best method is to insert a fine tube along the lumen of the large one and allow some warm saline solution to flow slowly along it into the abscess cavity, the fluid returning along the larger tube. If two tubes have already been inserted into the abscess cavity, the fluid injected through one will escape by the other. Whatever method is employed, care must be taken that there is free exit for the fluid, as otherwise the abscess cavity may become over-distended, and in consequence rupture of a portion of its wall may take place, especially the inner, which perhaps only consists of a thin layer of brain tissue separating the abscess from the lateral ventricle. During the act of irrigation there is a risk of some of the fluid, now loaded with septic particles, escaping between the surface of the brain and the dura mater and thus setting up a secondary meningitis.

Opening of a cerebellar abscess. The cerebellum may be explored from two different points, either in front or behind the lateral sinus. The posterior route is adopted if the abscess is superficial in the outer portion of the lateral lobe, usually the result of lateral sinus thrombosis or disease of the posterior mastoid cells. The anterior route is indicated if it is thought that the abscess is deeply placed in the anterior inferior portion of the cerebellum, that is, in those cases in which it is apparently a complication of labyrinthine suppuration, or the result of disease of the inner wall of the antrum and mastoid cavities (Fig. 253).

(a) Behind the lateral sinus. After exposure of the lateral sinus the bone is removed either by means of the gouge and mallet or by bone-forceps, until a considerable area of the dura mater is exposed behind and below the curve of the sinus (Fig. 253). The dura mater is then incised as already described.

The cerebellum is explored by thrusting the instrument inward for about an inch. As a rule the abscess is found at once. If it be not discovered at the first attempt, the instrument should be directed forwards, upwards, and inwards towards the posterior surface of the petrous bone. Care, however, must be taken that it is not pushed in too far, otherwise it may pierce the anterior upper margin of the cerebellum, and if an abscess be present, the meninges may thus become infected. If the surgeon has exposed the dura mater by trephining, it is necessary to push the exploratory instrument at least two inches inwards and forwards in order to reach an abscess situated in the anterior inferior portion of the cerebellum. In such cases it is by no means difficult to miss a small abscess, and further, drainage is frequently incomplete when an abscess is discovered. For this reason, if the cerebellum be explored first behind the lateral sinus and no abscess is discovered, it should further be explored by the anterior route in front of the lateral sinus. If the cerebellar abscess be secondary to lateral sinus thrombosis, and if there be no doubt as to the diagnosis, the inner wall of the sinus should be made as aseptic as possible, and the dura mater forming it incised freely; the cerebellum being thus explored through the site of infection.

(b) In front of the lateral sinus. The lateral sinus is first exposed (Fig. 253). The triangular area of bone situated in front of it, between it and the semicircular canals, and forming the inner boundary of the antrum and mastoid cavities, is now removed with the gouge and mallet or with a suitable pair of forceps. If it be certain that internal-ear suppuration exists, or if the operation be secondary to opening of the labyrinth, the posterior wall of the petrous bone may be removed until the internal auditory meatus is almost reached. If, however, the labyrinth be intact, care must be taken not to chisel away too much bone for fear of encroaching on the posterior semicircular canal. On exposure of the dura mater an extra-dural abscess may be met with, usually the result of internal-ear suppuration. Even if no pus be seen, it is always a wise precaution, if internal-ear suppuration coexists, to separate the dura mater from the posterior wall of the petrous bone by means of an elevator in order to prevent any deeply situated extra-dural abscess being missed. After the dura mater has been exposed sufficiently it is opened by a crucial incision. In this region absence of increased tension within the brain and lack of bulging outwards of the cerebellar tissue do not necessarily imply the absence of an abscess; the cerebellum to all appearances may appear normal and flaccid, although a small abscess may be present.

The cerebellum is explored in various directions to a distance of not more than one inch. After the pus has been evacuated a tube is inserted as described above. In the majority of cases this method is far superior to opening the cerebellum behind the lateral sinus, especially as it is now recognized that the chief cause of cerebellar abscess is internal-ear suppuration.

After-treatment. This is similar to that of any ordinary abscess, but care must be taken that free drainage is maintained. The main part of the mastoid wound is lightly plugged with gauze, the tube inserted into the brain abscess being brought flush with the surface of the skin. The gauze filling the wound cavity should be arranged around the tube so that it rests comfortably within the wound and is not kinked. If the drainage tube be in its proper position, pus should be seen to ooze out of it.

Although the mastoid cavity itself need not be dressed daily, if necessary the outer dressings may be removed twice a day, in order to see that drainage of the abscess is continuous. After the first two or three days, the tube is gradually shortened. If the abscess be a recent one and not encapsuled, it becomes rapidly obliterated by pressure of the surrounding brain tissue, so that the tube may be forcibly ejected within a few days. On the other hand, if the abscess has existed for a considerable period and is bounded by a thick wall, which may be extremely resistant, the purulent discharge may continue for many days and necessitate the continuance of drainage. Generally speaking, the tube may be shortened every second or third day, and can usually be dispensed with by the end of the second week, if not before. It is, however, very necessary that the tube should not be withdrawn until it is certain that the abscess cavity has been obliterated completely.

The general treatment of the case in no way differs from that already described for the mastoid operation in which the wound has been left open posteriorly.

Complications. (i) On turning back the flaps of the dura mater, a hernia, consisting of friable congested brain tissue, may occur at once. This is extremely rare as a result of a simple abscess of the brain, but is significant of encephalitis frequently associated with meningitis (see p. 436). If an abscess be suspected, the brain should be explored as already described. If, however, no abscess be discovered, the treatment consists in removal of more bone and further incision of the dura mater, in order to permit of free drainage and to relieve tension.

(ii) Opening into the lateral ventricle. This may be due to rupture of its wall owing to the sudden diminution of pressure from too rapid drainage of the abscess cavity, or it may occur accidentally from thrusting in the exploratory instrument or drainage tube too deeply. Its occurrence is evidenced by the sudden gush of cerebro-spinal fluid. The ultimate danger is subsequent infection of the cavity, which, unfortunately, frequently occurs.

(iii) Cessation of breathing. This is more likely to occur in a cerebellar abscess in consequence of direct pressure on the medullary respiratory centres. The immediate treatment is to do artificial respiration and to open the cerebellar abscess by the quickest method possible. If this be successful, respiration probably will be restored.

Prognosis and subsequent progress. In an uncomplicated case a favourable prognosis may be expected, provided the abscess is successfully opened and drained without much disturbance of the surrounding parts. Many factors, however, may lead to a fatal result. With regard to recovery: in 100 cases taken from the records of the London Hospital during the last ten years, recovery took place in 20% operated on for cerebral and 10% for cerebellar abscess. Other statistics give a much higher percentage of recovery, but it must be remembered that in hospital patients a large number of the cases are only seen by the surgeon at a very late stage, when the brain abscess is complicated by other intracranial or suppurative lesions, and the patient is in an almost moribund condition; so that the operation may only be undertaken as a forlorn hope.

If the operation is going to be successful, the head symptoms quickly disappear. Even if the patient was comatose before operation, the recovery may be so rapid that his mental condition may be almost normal within twenty-four hours. In many cases, if the abscess be a large one, convalescence will be tedious or prolonged; sometimes, indeed, complete restoration of the mental faculties, in spite of a most successful operation, will not be obtained. The chief relief to the patient is the cessation of the terrible headaches from which he has been suffering.

Unfavourable symptoms are the sudden onset of pyrexia accompanied by delirium usually the result of diffuse meningitis, or of infection of the lateral ventricles. In the latter case there is a rapid termination in drowsiness, coma, and death.

Although the brain abscess may be draining freely, the patient for some days may lie in a semi-comatose condition as a result of oedema or inflammation of the surrounding brain tissue; in such cases prognosis is difficult, but hope of recovery may be entertained if the pulse and temperature keep practically normal.

Recurrence of symptoms. This may take place within the first few days after the operation as a result of infective cerebritis, the presence of another abscess, or faulty drainage; or at a much later period, owing to the formation of another abscess or to a cyst within the brain at the site of the former abscess.

1. If the recurrence of the symptoms appears immediately after the operation, the wound should be inspected carefully, if necessary under an anÆsthetic. If drainage be not free, the tube should be removed and a pair of forceps inserted along the track leading into the abscess, their blades being then slightly opened and withdrawn. On doing this an accumulation of pus may escape. The cavity may then be irrigated gently with saline solution and a larger tube inserted.

If, however, this procedure does not give a satisfactory result, the finger may be inserted into the brain to feel if the abscess is loculated. By this means any existing septa may be broken through; or if a feeling of resistance suggests the presence of another abscess, this part of the brain can also be explored. It must also be remembered that although a temporo-sphenoidal abscess has been opened successfully and is draining well, the continuance of the symptoms may be due to a coexisting abscess of the cerebellum, or vice versa; in other cases, in spite of all care, the patient gradually sinks, partly from exhaustion and partly from general toxÆmia, the result of infective cerebritis.

2. Recurrence of symptoms at a later period. The occurrence of a fresh abscess is usually owing to the fact that the primary focus of the disease has not been completely removed at the first operation; for instance, if the surgeon only trephined and drained the abscess without performing the mastoid operation.

A cyst is usually the result of the abscess having been encapsulated and its wall not having been removed at the first operation. If a cyst be discovered on exploring the brain in consequence of these symptoms, its wall should be removed if possible.

Apart from symptoms of intracranial pressure, the patient may suffer from attacks of Jacksonian epilepsy from time to time, presumably due to the post-operative adhesions. If they continue in spite of conservative treatment, it may become necessary to operate in order to remove this source of irritation (see Vol. III).