The following causes have been noticed as originating spontaneous puer peral fistulte; rupture of the cervix and the vesico-vaginal septum when the head advances and the parts are rigid and cicatricial; cases of Berdot, Kiwisch, Detroit and others. The literature of this branch of our sub ject has been collected by F. L. Meissner and Duparcque-Nevermann.
Further to be noted are pressure effects when there are exostoses of the pelvic wall, vesical calculi, and carcinomata of the cervix and vagina.
Then the necrosis of gangrenous or diphtheritic parts, especially when there is a narrow pelvis, may occur. Simple necrosis during delivery of a woman with a narrow pelvis is common; in the other conditions it is rare, partly because the patients usually die before it can occur, and partly these processes most often affect the introitus vaginte and the pos terior vaginal wall, and do not disturb the bladder. The extent, the seat, and the time of origin of these fistuhe vary greatly in accordance with the structure of the tissue affected, the amount of blood it contains, its infiltration with serum, the length of time the pressure is continued, and its intensity, and the nature of the contusing body. So the contusions caused by the skull of the infant in a small pelvis appear as round and striped red patches, or as round, dry, colorless, gray, punched-out places. They are e,ast off by process of ulceration, and usually leave a circular loss of tissue behind. The seat of the injury varies in accordance with whether the contusion is at the entrance of the pelvis, or in the true pelvis. In the latter case it is usually close behind the urethra in the fundus vesicte; in the former it is high up in the vaginal portion. A resistant and large head predisposes to the accident, as does hydrocephalus (e,ase of G. Simon, Rostock. Krankenhaus, No. 3; case of author, see below), and faulty position. A pendulous abdomen also predisposes, though not to the ex tent that Esmarch would have it. The mechanical hindrance which a nar row pelvis presents, cannot be so easily overcome as can that caused by a pendulous abdomen; in fact the latter is usually in a relaxed condition due to the presence of the former. Schatz maintains that the expulsive force is exerted mainly by the abdominal walls, but it is not to be doubted that the uterine muscle does take part in the crushing of the soft parts. Face presentations often cause urinary fistulty (cases of Schupp, Danyau, cra niotomy; Metzger, cases 26 and 33 of Simon, and cases 2 and 17 of the author); the sharp edges of the child's face being very apt to do damage, especially as the presentation usually occurs with contracted pelves. Hecker claims that unusual height of the pubic symphysis also predisposes to abnormal pressure.
Several spontaneous fistulm may occur at the same time. In the author's case, No. 7, there were 4 openings. Here the gangrene occurs from pres sure successively or simultaneously applied to different portions of the soft parts. and even if only one part is implicated, the pressure may have
been uneven, and bridges of living tissue be left, so as to give us several orifices.
There was a time when the occurrence of vesico-vaginal fistula was sup posed to be largely due to the execution of certain obstetric operations, and especially to those that involved the use of the forceps. In 1828 W. S. Schmidt vigorously combatted this prejudice, and claimed that the accident would be of far less frequent occurrence if there was not such an ingrained fear of the use of the instrument. Even the teachings of the schools incule,ated a reluctanee to use the instrument which was a direct cause of the evil which it was sought to avoid; since in by far the greater number of cases it is the continued pressure of the impacted bead which causes the fistula. We are not so much afraid of the forceps now. Ch. West (1858) and G. Simon and Baker Brown have recorded it as their opinion that in most cases it is the postponement of instrumental assistance in tedious labors which causes the lesion. Perhaps the truth of the matter lies between these two extremes. In Bouque's collection of 204 different fistuke, 118 occurred after labor; of these latter 65 or 55 per cent., more than half, were instrumental confinements. I have myself operated upon a large number of fistulte in cases in which delivery had been effected by artificial means, and in almost every case it could be sat isfactorily proven that the operation was the cause of the fistula. This can only be decided by a thorough considemtion of the seat, size, shape, and edges of the loss of tissue. The presence of extensive scars or adhe sions, or of stenoses or atresias of the vagina, will render probable the in jury of the parts by the forceps themselves. In 28 cases of vesico-vaginal fistula upon which Spiegelberg operated (Landau, p. 343), 22 occurred after instrumental labors, 17 were in primipara‘, 11 in multiparty, and half of all the cases had stenoses, cicatricial bands, and atresias. The fis tube occurring after normal delivery are mostly situated in the upper part of the vagina, and are either superficial or deep utero-vesico-vaginal fis tulte, or utero-vesical fistulie. Thus in 15 cases of uterine fistula that Spiegelberg operated upon, 12 were after simple, and 3 after instrumen tal deliveries, 12 were primiparous and 3 multiparous. As complicating causes we may mention premature rupture of the membranes, non-dilata tion of the cervix in spite of long-continued pains, and in the deep utero vesico-vaginal fistulEe, tardy opening and canalization, especially in cervices ruptured at earlier births. Naturally the existence of these conditions cannot always be ascertained by observers who were not present at the delivery.