Evaluation of the biofragmentable anastomotic ring following preoperative irradiation to the rectosigmoid in dogs.

An animal study was done to evaluate the safety of a sutureless colorectal anastomosis in irradiated bowel. Forty mongrel dogs received preoperative radiation with 5000 rads and then underwent a low anterior resection and anastomosis using either the EEA-31TM stapling device, a two-layer handsewn technique, or the biofragmentable anastomotic ring (BAR) 31-1.5 mm and BAR 31-2.0 mm devices. The anastomoses were then evaluated for early and late anastomotic healing and leaks. The results show four radiographic (three clinical) leaks (P less than .05) in the BAR 31-1.5 mm group and one radiographic leak in the handsewn group. No leaks were detected in the EEA or BAR 31-2.0 mm groups. Results indicate that all three techniques can be done safely with this dose of radiation, and gap size (1.5 mm vs. 2.0 mm) is of critical importance when performing a BAR anastomosis in irradiated bowel.