Clinical and Physiological Factors Affecting Postoperative Anal Dysfunction After Low Anterior Resection for Rectal Cancer

In order to clarify clinical and physiological factors affecting the severity of anal dysfunction after low anterior resection (LAR) for rectal cancer, anorectal physiological analysis was carried out preoperatively and between 5 and 7 months postoperatively in 22 patients undergoing LAR. The severity of anal dysfunction was scored between 0 (best) and 6 (worst) according to the daily bowel frequency, the presence or absence of soiling and its frequency, and the severity of urgency for defecation. Postoperative anal function was poor in patients having an anastomosis close to the anal margin and in patients whose neorectal capacity was small. By using a multiple regression analysis in which clinical factors and preoperative physiological parameters were used as independent variables, the severity of postoperative anal dyfunction was found to be predictable due to the age of patient, the distance between the anastomosis and the anal margin, preoperative maximum tolerable volume of the rectum, and preoperative anal mucosal electrosensitivity. It was suggested that an attempt to increase the postoperative neorectal capacity may be useful in reducing postoperative anal dysfunction after LAR.