Primary repair of obstetric anal sphincter rupture using the overlap technique

Objective To evaluate the feasibility of a new technique of primary overlap anal sphincter repair instead of end-to-end repair. Setting A teaching hospital and a district general hospital. Methods Between June 1995 and November 1996, two obstetricians repaired 32 anal sphincters ruptured during vaginal delivery. A ruptured internal sphincter was repaired separately and the torn ends of the external sphincter were overlapped and sutured with 3/0 polydioxanone sulphate sutures (Ethicon, Edinburgh, UK). Main outcome measures Bowel function, clinical assessment, anal endosonography and manometry performed at a mean of 140 days after delivery. Results Eight percent of the women experienced incontinence of flatus. Fifteen percent had persistent sonographic external sphincter defects, and 44% had internal sphincter defects. The maximum mean resting pressure was 58 mmHg (range 37-135) and the mean maximum incremental squeeze pressure 54 mmHg (range 8-104). None had defaecatory difficulty and no complications were encountered with the new technique of repair. Conclusions Reservations regarding the feasibility of the overlap technique of primary repair are unfounded, as both subjective and objective outcomes are favourable compared with other studies using end-to-end approximation. A multicentre randomised study of the overlap vs end-to-end repair technique is now planned.