Integrity of the Anal Sphincters After Pouch-Anal Anastomosis: Evaluation With Three-Dimensional Endoanal Ultrasonography

PURPOSE: METHODS: RESULTS:Fifteen patients with a colonic pouch and 13 patients with an ileal pouch were examined. Six months after the procedure, three-dimensional endoanal ultrasonography showed significant alterations of the internal anal sphincter in eight patients with a colonic pouch-anal anastomosis (53 percent) and in eight patients with an ileal pouch-anal anastomosis (62 percent). These alterations were characterized by asymmetry or thinning. No defects were seen in the colonic pouch group, but, in two patients with an ileal pouch, a small defect in the internal anal sphincter was found. A decrease in internal anal sphincter volume was seen only in patients with a colonic pouch-anal anastomosis (P = 0.009). In both groups the length of the internal anal sphincter and the length, thickness, and volume of the external anal sphincter remained the same. After the procedure a reduction of maximum anal resting pressure was found in both groups (colonic pouchP < 0.001, ileal pouchP = 0.001). Maximum anal squeeze pressure was reduced in only patients with an ileal pouch-anal anastomosis (P = 0.006). The observed alterations of the internal anal sphincter and the manometric findings showed no correlation with the postoperative Fecal Incontinence Severity Index scores. CONCLUSION: