Edward Rigby

ENCYSTED PLACENTA.

Situation in the uterus.—Adherent placenta.—Prognosis and treatment.—Placenta left in the uterus.—Absorption of retained placenta.

By the term encysted placenta, we mean that state of irregular uterine action after the expulsion of the child, where the lower portion of the uterus, particularly the os uteri internum, is closely contracted, while the fundus contains the placenta enclosed in a species of cyst or cavity formed by itself and the body of the uterus.

Upon examination externally, we find the fundus pretty firmly contracted, but probably somewhat higher up the abdomen than usual; the vagina and os uteri externum, or os tincÆ, are usually found dilated, the passage gradually tapering like a funnel to the os uteri internum, or upper end of the canal of the cervix.

Situation in the uterus. This state has been very generally considered to arise from a spasmodic contraction in the circular fibres of the body of the uterus, by which it was as if tightly girded by a cord at its middle, and, from the form it was supposed to take, was called hour-glass contraction of the uterus.

From the observations of later years there is much reason to suppose that the true hour-glass contraction, as now described, is of very rare occurrence, even if it does take place at all; and that, in by far the majority of cases, the stricture is either produced by the upper part of the cervix, as we have already mentioned, or resides in the os uteri externum or inferior portion of the cervix.

Baudelocque was the first who pointed out the neck of the uterus as the real seat of the stricture in these cases: “that circle (says he) of the uterus which is round the child’s neck, according to the general laws of its contraction, must narrow itself much quicker after delivery than the other circles which compose that viscus, because it is already narrower, and its forced dilatation at the instant of the expulsion of the child’s trunk is only momentary, and because it has naturally more tendency to close than the other circles have, since it is that which constitutes the neck of the uterus in its natural state.” (Baudelocque, Heath’s Trans. vol. ii. § 969.)

Dr. Douglas, of Dublin, also investigated this subject, and came to a similar conclusion: he considered that encysted or incarcerated placenta from hour-glass contraction, resulted either from morbid adhesion of the placenta, or from inactivity of the uterus, and does not occur as a primary affection; his observations lead to the conclusion that the stricture in hour-glass contraction “does not form from the middle circumference of the uterus; it is formed by the lowest verge of its thickly muscular substance, at the line of demarcation of its body and cervix.” “Thus, then, it would appear that the upper chamber comprises in its formation the entire of the body of the fundus; whilst the lower chamber engages only the cervix uteri and the vagina.” (Medical Transactions of the Col. of Phys. vol. vi. p. 393.)

The late W. J. Schmitt of Vienna considered that the stricture was produced by the os tincÆ, or os uteri externum.

From our own experience we would say that the seat of the stricture varies considerably in different cases; that in the simplest form it is nothing more than a contracted state of the os uteri externum; that in others it is formed by the upper portion of the cervix uteri, or os uteri internum; but in other instances it appears to be formed by the inferior segment of the uterus itself. The contraction in this part of the uterus, which, according to the observations of Professor Michaelis, comes on when the os uteri is fully developed, and, by closely surrounding the head, is one chief means by which prolapsus of the cord is prevented, may easily produce a state of stricture after the birth of the child, and thus retain the placenta; it may, however, be questioned whether this portion of the uterus, when fully dilated by pregnancy, and which then forms its inferior segment, would not become the os uteri internum when the uterus is empty and contracted.

Hour-glass contraction of the uterus is liable to occur where the action of the uterus has been much deranged or exhausted, either by the unusual rapidity or excessive protraction of the labour. In all cases where the child has been rapidly expelled before the uterus has had time to contract regularly and uniformly, the disposition in the os uteri to contract, as pointed out by Baudelocque, will manifest itself. This state may also be induced by great previous distention, as from twins, or too much liquor amnii; by irritation, as by improperly pulling at the cord, by having used too much force in artificially delivering the child, by the introduction of the hand or instruments too cold, &c. The most frequent cause, however, is over anxiety to remove the placenta; the cord is frequently pulled at, and at length the os uteri is excited to contract; in this case we generally find the stricture at the os tincÆ, which yields without much difficulty, either by gentle friction with the hand over the fundus, and cautiously pulling the placenta in the axis of the superior aperture, or by introducing the hand and bringing it away.

Adherent placenta. When the placenta is still attached either wholly or in part, there are generally some preternatural adhesions to the uterus, which, by keeping its upper portion distended, give rise to partial contractions below. This condition of the placenta is observed to attend nearly every severe case of hour-glass contraction; in some instances its whole surface appears as if grown to the uterus, forming an adhesion so close and intimate as to be overcome with the greatest difficulty: we have met with cases where the placenta tore up into shreds which still adhered to the uterus as strongly as before; in others, however, the adhesions are of smaller extent, varying from the size of a shilling to that of a crown piece, sometimes there being only one, sometimes two or three in the same placenta.

The nature of these adhesions is but little understood; it is generally considered that they have been produced by some inflammatory process taking place between the uterus and placenta; and certainly the firm feel and lighter colour of the part which has been adherent might, perhaps, justify such a conclusion. Cases have occurred where the inflammatory action has extended in the contrary direction (outwards,) producing mischief in the neighbouring parts, viz. abscess and injury of the pelvic periosteum with subsequent pelvic exostosis. (Neue Zeitschrift fÜr Geburtskunde, band v. heft 1.) We may also observe, that these adhesions of the placenta usually occur several times in the same individual.

Prognosis and treatment. The danger in these cases depends chiefly on the presence or absence of hÆmorrhage; in the latter case, we may wait safely, and give the uterus the opportunity of contracting upon the placenta, so as ultimately to dilate the stricture and expel it. In most instances, where the os tincÆ is the seat of the contraction, and the placenta (as is usually the case here) already detached, a little patience, aided by gentle friction of the fundus, and carefully abstaining from all irritation of the os uteri, will be sufficient to attain this object; the os uteri will gradually relax and the placenta slowly exude into the vagina. Where, from the feel of the fundus, the uterus appears still unable to exert such a degree of contraction as shall overpower the os uteri, we may follow the plan of Dr. Dewees, in his section “On the enclosed and partially protruded Placenta,” and rouse its activity by some doses of ergot: “should this not succeed within an hour, the uterus must be gently entered, by slowly dilating the os uteri, and the placenta removed.” One finger after the other must be passed through the os uteri, until it has yielded sufficiently: if the placenta be quite detached, two fingers will generally be sufficient for this purpose, by which means it may be gradually brought down into the palm of the hand, and then removed.

Where more or less of it is morbidly adherent, which may be presumed when it continues for some time at the upper part of the uterus without any disposition to descend, we must carefully introduce the whole hand, and endeavour to find the edge of the placenta at which we should begin the process of separation. Where, however, the edge is very thin, and the attachment firm, it is not easy to effect this without risk of injuring the structure of the uterus itself with the nails, nor can we always distinguish the thin and closely adherent edge of the placenta from the uterus itself: in these cases it will be safer to plunge the fingers into the central and thicker portions of the mass, and gradually separate it towards the circumference. Wherever this close adhesion prevails over a considerable extent, it becomes nearly impossible to prevent portions being left adhering to the uterus; thus it not unfrequently happens, where a placenta under these circumstances has been artificially removed, that there are one or more large irregular cavities on its uterine surface, from a portion of its mass having been torn from it, and left adhering. Cases have occurred to us,[134] where the whole central portion has thus remained, the amniotic surface of the placenta having come away entire with the larger umbilical vessels attached to it, and merely a narrow margin of parenchyma at its edge; in others, the whole mass has broken up, the cord, the larger branches of the umbilical vessels, and the membranes have come away, but the greater part of the placenta has remained closely adhering to the uterus. In such a case it becomes a question, whether it be safe to persist in our efforts to remove the remains of the placenta, or whether it will not be better to leave the case to nature: experience shows that the latter plan is the safer, and that a practitioner is not justified in running the risk of severely injuring the uterus by repeated and violent efforts to effect his object.

Placenta left in the uterus. Where a portion of placenta has been thus left in the uterus, the case may terminate in one of three ways: either it may be expelled in the course of from twelve to twenty-four hours, without any perceptible marks of putrefaction, and with but little or no disturbance to the system; or where, after a longer interval, the discharges have become very offensive, and the placenta has been expelled in a putrid state, with serious disturbance of the health; or lastly, where the lochia has been sparing but natural, and where no trace whatever of the placenta has appeared.

In the first mode of termination it may be presumed that the attachment of the placenta has yielded either to the continued contraction of the uterus, or from a slight degree of incipient putrefaction, by which its union with the uterus was weakened; in the second case, from contact with the external air, and being constantly kept at a considerable temperature by the heat of the surrounding parts, the lacerated placenta rapidly putrefies, putrid matter is carried into the system, producing all the effects of a deadly poison, and the patient is placed in a state of the greatest danger; the pulse becomes quick and small, the tongue red and dry, accompanied with great depression of the vital powers, the uterus frequently swells, grows hard, and excessively painful, followed by general peritonitis; it is not, however, the inflammation which necessarily destroys the patient, but the prostrating effects upon the nervous system, produced by the introduction of an animal poison into the circulation.

Absorption of retained placenta. Where the placenta has not been much lacerated, or at any rate where every portion has been removed which could be separated without violence, where also the uterus has contracted firmly and closely, the part which is retained does not pass into putrefaction, little or no inconvenience is experienced by the patient; the lochia, as we before observed, is sparing but natural, and ceases after the usual time, but not a trace of the placenta comes away. This fact has been repeatedly noticed, especially in later years; but the attention of medical men was first called to the subject by Professor NaegelÉ, of Heidelberg, in 1828. In 1802, and again in 1811, cases of premature expulsion of the foetus occurred to him where the membranes and placenta did not come away, and where no trace whatever of them appeared afterwards. In 1828[135] his assistance was required in a case of unusually firm adhesion of the placenta, and where, from this as well as other circumstances, the extraction was so difficult that he was compelled to leave considerably more than one-third in the uterus. (Med. Gaz. Jan. 10, 1829.) About the same time, a most interesting case was published by Professor Salomon, of Leyden, where the whole placenta of a child only three weeks short of the full time was retained by the firm contraction of the uterus, and, according to Dr. Salomon’s view of it, removed by the process of absorption. About the end of the third week, the uterus, which had hitherto been larger than is natural under ordinary circumstances after labour, and more globular, now diminished considerably, and began to assume the usual form as in the unimpregnated state. Besides the cases already alluded to, which we have described in our Midwifery Hospital Reports, we may again refer to one which was mentioned by Dr. Young, formerly professor of Midwifery at Edinburgh: “I could get my hand to the placenta, but no farther, the uterus having formed a kind of pouch for it, so that I at last was obliged to trust to nature; what was very remarkable, the placenta never came away, yet the woman recovered.”

Cases have also occurred where the placenta, after having been retained many days in the uterus, has been expelled quite fresh, the edges worn or rather dissolved away by the process of absorption; thus Dr. Denman mentions one where the whole placenta was retained till the fifteenth day after labour, and was then expelled with little signs of putrefaction except upon the membranes, the whole surface which had adhered exhibiting fresh marks of separation. Cases of abortion have occasionally been observed where the embryo has escaped, but the secundines have never come away, although the discharges, &c., have been watched with the greatest attention; after a time the menses have returned, the patient has again become pregnant, and has passed through her labour at the full term without any thing unusual occurring.

The subject has recently been considered very fully, and much interesting knowledge added, by Dr. Villeneuve, of Marseilles. Besides putting the fact beyond all doubt, he shows that cases of total adhesion are rarely if ever fatal; and that, where cases have terminated fatally, the placenta has only partially adhered, and the patient has been either destroyed by hÆmorrhage, or by the effects arising from the absorption of putrid matter, or from injury of the uterus in attempting to remove the placenta. He considers that a placenta which is not fixed to the uterus by organic and intimate adhesions cannot be absorbed, though it may perhaps be retained for several days without danger, if there is contraction of the uterus. (Gazette MÉdicale de Paris, July 8, 1840.) It may, however, be doubted whether this last observation be correct, as it is a well-established fact that cows which had been supposed with calf, and in which the symptoms of pregnancy had again subsided, have afterwards been killed and nothing but the bones of the calf found in the uterus, the soft parts having been removed by absorption. The same fact has been observed also in sheep and other animals; and knowing how abundantly the human uterus is supplied with absorbents, coupled with what has been already stated, there can be little or no doubt but that the placenta in these cases had been acted upon by a similar process. Although we strongly deprecate repeated attempts to remove the adherent portions of placenta, especially where we have brought away a considerable quantity of its foetal part, still we would warn our readers against leaving any loose ragged pieces in the uterus, for these rapidly pass into putrefaction, and produce the alarming symptoms above-mentioned. The safety of our patient mainly depends on the firm contraction of the uterus preventing the access of air, and on our constantly removing, by means of injections, any putrid discharge which may have collected. The sparing quantity of lochia which has generally been observed, especially where the whole surface of the placenta has adhered, can easily be accounted for, the greater portion of the vessels which ordinarily furnish this discharge being closed up by the adherent mass: from the same reason we can explain why cases of total attachment of the placenta are rarely or never attended with hÆmorrhage.

Lastly, should any symptoms of fever or abdominal inflammation supervene, they must be treated according to the rules which we have given under these heads.[136]