RECTO-VAGINAL FISTULA.
In reference to the regional anatomy of the recto-vaginal septum these fistulte affect ordinarily the lower (perineal) and middle (rectal) divisions of the posterior vaginal wall. Exceptionally they are also found in the upper division, the peritoneal, the fistula extending from the vagina through Douglas's pouch into the rectum. They result either from trau matic causes, or else aside from these, through necrotic and ulcerating circumscribed sloughing of the recto-vaginal septum.
Most frequently fistulte result during labor, in particular where the obstacle to delivery is gre,at. Contrarywise to that which holds for ves ico-vaginal fistula3, the cause is rarely prolonged pressure, since the recto vaginal septum, except in funnel-shaped pelves, or where there is anchy losis of the coccyx, is seldom for any length of time exposed to pressure, the reverse being true of the vesico-vaginal septum. In the majority of cases the fistulte have their origin in lacerations of the distended posterior vaginal walls. The deep recto-vaginal fistulte result either after rupture of the posterior commissure or else after complete rupture of the peri neum.
Above the perineal division of the recto-vaginal septum, fistulte result from obstacles to delivery due to abnormal tension above stenosed parts, to tumors, or to pelvic contmction. Narrowness and rigidity of the vagina lead, ordinarily, to laceration which often extends into the rectum. Generally traumatism during difficult labor is the cause of fistulm. For ceps, manual extraction, cephalotripsy, etc., play a large part in the etiology of recto-vaginal fistulte. Opemtions on the genital organs for atresia, the extirpation of tumors from the posterior vaginal wall, etc., are also factors. Unskillful administmtion of enemas may result in perfora tion of the recto-vaginal septum, and I have myself noted such an instance in a puerpera. We have already noted the fact that foreign bodies may cause fistulae, in particular pessaries. The seat of the fistulle varies greatly, those in Douglas's togas, accompanied by prolapse of intestines, being of peculiar interest. Degenerated extra-uterine gestation sacs and ovarian cysts, may ulcerate through Douglas's pouch, and leave a fistu Ions tract; and further still, pelvic abscesses, diphtheritic and syphilitic ulcers, carcinoma and other new growths.
The etiological factors noted act almost entirely in the adult. Recto vaginal fistulte have very seldom been met with in children. Bednar re ported an instance in a four weeks olcl infant, from gangrene of the vagina. Tbe separation of the slough was followed by a fistula. Cellulitis of the right arm complicated the caae, and the child died on the 21st day. G. T. Witter has recently recorded an instance in a seven months old child. For some months it had been troubled with aphtlue, was much emaciated and complained of great pain on defFecation. Passage of ffecal matter by the vagina was noted and on examination a fistulous communication betwe9n the rectum and the vagina was found. With improvement in the child's general condition, the administration of enemas, the tam ponade of the vagina with cotton dipped in carbolized glycerin, the fistula closed, and the child was discharged in ten days.
Aside from the cause of the fistula, the length of time that it has ex isted has an influence on the size. There is present a tendency to cica tricial contraction. Generally the fistula, when not caused by extensive breaking down of new growths, appears as a roundish gap on the vaginal and the rectal walls. When caused by traumatism one opening is gener ally larger than the other, the larger being on that wall where the trau- - matism or ulceration began. In case of ulceration this is not always so, since the suppuration may extend and a secondary outlet may communi cate with the first. A valve over the vaginal opening of the fistula is often formed by overlapping' of the resisting muscular layer of one of the vaginal rugte. In a twenty-nine year old woman under my observation, who had a funnel-shaped fistula extending downwards obliquely towards the rectum, the vaginal opening was covered by a tongue-like valve from the lower end of the columna rugarum. The fistula dated from her first delivery, which was a difficult one. Immediately after delivery there was hemorrhage from the vagina and the rectum, and on the sixth day there after passage of watery fmces and flatus by the vagina. In case of high seated recto-vaginal fistulm, the vaginal opening is often directed from the mid-line, and fixed there by a cicatricial band. In two instances I noted this deviation to the left.