Impact of Pelvic Radiotherapy on Morbidity and Durability of Sphincter Preservation After Coloanal Anastomosis for Rectal Cancers

Purpose This study was designed to assess the impact of pelvic radiotherapy on the incidence of complications and colostomy-free survival of patients after a coloanal anastomosis for rectal cancer. Methods A total of 192 patients underwent a coloanal anastomosis between 1982 and 2001: 87 patients did not receive pelvic radiotherapy; 105 patients received pelvic radiotherapy (39 preoperative and 66 postoperative). Early and late complications requiring surgical intervention and the colostomy-free survival rate were assessed by retrospective review of patient records. Results After a median follow-up of 62 months, 151 patients were alive. The most frequent complication was development of an anastomotic stricture (5-year rate of a stricture, 16 percent; 95 percent confidence interval, 10–21). Patients receiving pelvic radiotherapy had a higher rate of complications other than anastomotic strictures, including fecal incontinence, fistulas, abscesses, and bowel obstructions compared with patients not receiving pelvic radiotherapy (5-year rate: 20 percent (95 percent confidence interval, 10–29) vs. 5 percent (95 percent confidence interval, 0–10); P = 0.001). Patients receiving pelvic radiotherapy had a lower colostomy-free survival than did patients not receiving pelvic radiotherapy (5-year colostomy-free rate: 72 percent (95 percent confidence interval, 62–84) vs. 92 percent (95 percent confidence interval, 86–98); P < 0.001). There was no significant difference in the colostomy-free survival of patients receiving preoperative and postoperative pelvic radiotherapy. Conclusions After coloanal anastomosis, a significant number of patients will have complications requiring surgical intervention, and some will require a permanent colostomy. Pelvic radiotherapy, whether it is administered preoperatively or postoperatively, significantly increases the need for a permanent colostomy.