Manometric squeeze pressure difference parallels functional outcome after overlapping sphincter reconstruction

PURPOSE: This study was designed to evaluate the effectiveness of overlappi ng anal sphincter reconstruction and to determine the manometric parameters that correlate with a successful functional outcome. METHODS: A retrospect ive review; of patients who had undergone overlapping sphincter reconstruct ion for anal incontinence from 1988 to 1999 was undertaken. Only patients w ith preoperative and six months-postoperative anal manometry were included in this study. Standard statistical tests were used to compare pre- and pos toperative findings. RESULTS: A total of 52 overlapping sphincter reconstru ctions were performed on 49 patients (46 females). The mean age was 44 (+/- standard error, 15.8; range, 20-81) years, with follow-up at six months. F orty-two patients had a history of complicated vaginal delivery (episiotomi es, tears, forceps delivery); 36 patients had a history of anal or perineal surgery; and two patients had perianal Crohn's disease. Nine patients (17 percent) had undergone prior sphincter repair. Incontinence grade improved in 37 patients (71 percent), and complete continence returned in 21 patient s (40 percent). The presence of a rectovaginal fistula, postoperative compl ications, previous sphincter repair, and increase in pudendal nerve termina l motor latency did not affect functional outcome (P = not significant). Pa tients older than 50 years had a better functional outcome than their young er counterparts after sphincter repair (P = 0.02). Although mean maximal sq ueeze pressure and mean anal sphincter length increased significantly after sphincter reconstruction (P = 0.0006 and 0.004. respectively), only squeez e pressure difference correlated with functional outcome (r = 0.37; P = 0.0 07). CONCLUSIONS: Overlapping sphincter reconstruction improved anal functi on in the majority of patients. The most important factor in the return to normal sphincter function is an increase in squeeze pressure.