Intestinal anastomosis after preoperative radiation therapy for carcinoma of the rectum.

A retrospective review was conducted on 133 patients who underwent anterior resection and primary intestinal anastomosis for adenocarcinoma of the rectum from 1973 to 1983 at the Baystate Medical Center. Forty patients received a moderate dose, 4,500 rads, of radiation therapy preoperatively. Twenty-six of these patients (65 per cent) underwent protective colostomy at operation. An additional 93 patients underwent an operation without radiation and 38 of these (42 per cent) had a colostomy. We found no significant difference between patients who did or did not undergo radiation therapy in the over-all rate of complications (25 per cent for those who underwent radiation and 29 per cent for those who did not). Furthermore, there was no significant difference in anastomotic leak rates between the two groups (10 and 7 per cent respectively), even after controlling for the presence of a protective colostomy. We did find that leak rates for both groups were markedly higher for patients with a colostomy (14 per cent) than for patients without (1 per cent) (p less than 0.005). We conclude that a moderate dose of radiation therapy preoperatively does not increase the risk of anastomotic leakage or other operative complications with anterior resection. Colorectal intestinal anastomosis may be safely performed without routine colostomy after planned preoperative adjuvant radiation therapy if the anastomosis is technically satisfactory.