Up to half of women reported with a ruptured anal sphincter sustained during vaginal delivery become incontinent. Reported rates of rupture range up to 2.5 percent where mediolateral episiotomy is practiced but as high as 7 percent after midline episiotomy. Most often an obstetrician performs a primary repair immediately after delivery by approximating the torn muscle ends with interrupted or figure-of-8 sutures (Fig. 1). Many women nevertheless suffer anal incontinence. Colorectal surgeons prefer an overlap repair technique, with which 75 percent of the patients reportedly become continent. This report reviewed the results of repair in 32 consecutive women who suffered a ruptured anal sphincter during vaginal delivery.
All repairs were done in an operating room under general or regional anesthesia and muscle relaxation. After identifying the torn muscle ends, they were mobilized and pulled across to overlap in a "double-breasted" manner (Fig. 2). The anal mucosa and internal sphincter were repaired as necessary before joining the torn ends of the external sphincter with 3/0 Ethicon (polydioxanone sulfate) sutures. The perineal muscles were reconstructed with 2/0 Vicryl sutures, and the vaginal epithelium with continuous 3/0 Vicryl sutures. Finally, subcuticular sutures were placed to close the perineal skin. I.V. antibiotics were given intraoperatively, and oral cefuroxime and metronidazole were continued for 1 week. Women were given stool softeners and a bulking agent.
A standard questionnaire asking about bowel and bladder symptoms was administered before and 3 months after repair. Manometry was done to record the peak resting and squeeze pressures, and anal endosonography was carried out. All but 1 of the 32 women had an overlap repair of the external sphincter, and 27 were followed up for about 42 months on average. Surgery was performed a median of 85 minutes after delivery and lasted a median of 70 minutes. Twelve women had an obviously torn internal sphincter repaired, but follow-up endosonography showed that other women had such a defect. The external sphincter overlapped sonographically in 82 percent of women; four of the remaining five women had a defect. No woman had persistent or perineal pain or trouble evacuating the bowel when followed up, and none developed an anorectal-vaginal fistula. Six women, nearly one fourth of those assessed, described stress urinary incontinence, and in four cases, this was a new symptom. Of 15 women who had resumed sexual activity, 2 described dyspareunia. In this study, an overlap repair of the torn anal sphincter yielded good subjective and objective results compared with those obtained by end-to-end approximation.
Departments of Obstetrics and Gynaecology and Colorectal Surgery, St. George's Hospital, London; Mayday University Hospital, Thornton Heath, Surrey; and Princess Anne Hospital, Southampton, U.K.
Br J Obstet Gynaecol 1999;106:318-323