Postoperative anal canal length predicts outcome in patients having sphincter repair for fecal incontinence

PURPOSE: Controversy exists in regard to the prognostic value of clinical d ata and physiological tests in patients undergoing sphincter repair for fec al incontinence. The aim of this study was to identify prognostic factors. METHODS: Between 1986 and 1996, 405 consecutive patients had a sphincter re pair for fecal incontinence. Preoperative and postoperative manometric data were available on 51 of these patients, and these patients' charts were re viewed retrospectively. Preoperative and postoperative continence was score d using the four-level scale of Browning and Parks. Mean follow-up was 16.2 (median, 6; range, 1-96) months. Mean age was 41 (median, 36; range, 21-80 ) years, and 46 (90 percent) patients were female. RESULTS: Twenty-three (4 5 percent) patients had perfect continence postoperatively, whereas 41 (80 percent) patients demonstrated improvement in continence score after sphinc ter repair. Using univariate analysis, various clinical and anal physiologi c data were analyzed for an association with postoperative continence score . Postoperative mean resting pressure and postoperative anal canal length w ere both significantly related to postoperative continence (r(s)(B) for Spe arman correlation coefficient to differentiate from r for the Pearson coeff icient. = 0.442; P = 0.0012; and r(s) = 0.440; P = 0.0012, respectively), w hereas postoperative mean squeeze pressure was not (r(s) = 0.273; P = 0.052 9). Postoperative mean resting pressure and anal canal length were entered into a logistic regression model. Postoperative mean resting pressure was n ot significant (P = 0.6643), and when it was dropped from the model, postop erative anal canal length was highly significant (estimated odds ratio, 3.2 ; 95 percent confidence interval, 1.1-9.3; P = 0.0047) in predicting postop erative continence. CONCLUSIONS: No preoperative data predicted functional outcome, and in contrast to other studies, postoperative anal canal length provides the best prediction of postoperative continence.