Clinical effects of preoperative radiation therapy on anorectal function after proctectomy and colonic J-pouch-anal anastomosis.

Abstract

Preoperative radiotherapy is increasingly used for certain rectal cancers, although some evidence suggests that it may adversely affect anorectal function. Reconstruction with a colonic J-pouch-anal anastomosis after complete proctectomy is thought to improve function, but few published data on pouch function after radiation exists. The aim of our study was to compare long-term bowel habits in patients receiving preoperative radiation for rectal cancer followed by colonic J-pouch-anal anastomosis with those of patients having similar rectal cancer surgery without radiation. Patients (n = 125) having undergone colonic J-pouch-anal anastomosis for rectal cancer, of whom 28 had preoperative radiotherapy and 97 did not, responded to a detailed questionnaire about their bowel habits at least 12 months after surgery, with a mean (+/- standard deviation) interval of 64 (+/-42) months. Radiation was administered preoperatively as a short (25 Gy over 5 days, n = 22) or long (45 Gy over 4 weeks, n = 6) course. All patients had colonic J-pouch-anal anastomosis with manual anastomosis at or immediately above the dentate line. Except for tumor stage, no preoperative difference was observed between the two groups. The number of bowel movements per 24 hours in patients with and without radiation was 1.8 (+/-0.8) and 1.8 (+/-1.5), respectively (P> 0.05). In the irradiated group, diarrhea (39 vs.13 percent, P= 0.005) and nocturnal defecation (36 vs.15 percent, P= 0.03) were more frequent than in the nonirradiated group. No other significant difference existed between groups with regard to stool clustering, use of protective pads, ability to defer evacuation >15 minutes, ability to evacuate the bowel within 30 minutes, incontinence score, use of medications, or dietary restriction. Preoperative radiotherapy followed by proctectomy and colonic J-pouch-anal anastomosis significantly increased nocturnal defecation frequency and diarrhea compared with similar nonirradiated patients but had no influence on the other bowel-habit parameters studied.