Physiologic characteristics of straight and colonic J-pouch anastomoses after rectal excision for cancer

PURPOSE: The colonic J-pouch anastomosis has been advocated to obviate urgent and frequent defecations following a sphincter-saving rectal excision. Physiologic characteristics of the colonic J-pouch were compared with those of the traditional straight anastomosis and related to clinical function. METHOD: Patients with total mesorectal excision for carcinoma were randomized to either a straight (n=23) or a colonic pouch anastomosis (n=23). The patients were examined before and at one year after surgery (n=42), which included laboratory studies, and a questionnaire regarding anorectal function was completed. RESULTS: Preoperative compliance of the rectum was restored after surgery in the pouch group, 2.9 (2.2–3.4) ml/cm H₂O, but there was a significant decrease after surgery in the straight anastomosis group, 1.9 (1.1–2.3)P<0.001 (median (interquartile range)). Sphincter pressures in both groups were similar. In a multiple regression analysis, high compliance was associated with favorable clinical function, and hypermotility of the anal canal was associated with adverse clinical function. CONCLUSIONS: Colonic pouch-anal anastomosis restores neorectal compliance, which is important for good function after low anterior resection. Presence of an unstable internal sphincter is a negative factor for clinical function in both straight and pouch anastomoses.Supported by the Research Funds of the University Hospital in Linköping and the County of Östergötland.