Peranal coloanal anastomosis following low anterior resection for rectal carcinoma

Abstract
Since 1978, 41 patients (12% of all restorative operations) have undergone perianal coloanal reconstruction following anterior resection (LAR) for cancers of the midrectum. Twenty-seven patients (66%) were men and 14 patients (34%) were women (mean, 58.8 yr. The mean distance of the primary tumor from the anal verge was 6.7 cm and 50% of the primary tumors were considered highly mobile. In 29 patients, a hand-sewn anastomosis was performed between the colon and the dentate line. In the 12 most recent patients, the anastomosis was performed using a circular stapling instrument. A diverting colostomy should be employed in all cases and is closed approximately 3 mo. later. There has been no operative mortality. Morbidity included anastomotic separation (2 patients), minor anastomotic defects (3 patients), pelvic sepsis (2 patients) and bacteremia of unknown origin (2 patients). Where fecal diversion was employed, there were no instances of anastomotic leak. Two patients with hemorrhage were returned to the operating room. Thirty-seven of the 41 patients underwent curative resections. Thiry-three% of the patients had Dukes'' C lesions. With a median follow-up of 31 mo. for the curative resections, 73% remain free of disease. Sixty-four% of evaluable patients have either excellent or good anorectal function 9-12 mo. after colostomy closure. Of 26 operations performed by 1 surgeon, 22 patients (85%) are currently evaluable. Nineteen (86%) of the 22 have normal or near-normal bowel function. Four guidelines for performing a functionally successful operation are presented. Coloanal reconstruction following LAR, where pull-through operations were previously required, is an excellent sphincter-preserving operation. The functional results 1 yr after the operation are gratifying, with the majority of patients leading an active life with normal bowel function.