Improved survival using oxygen free radical scavengers in the presence of ischemic bowel anastomosis.

A rat model was developed to determine the efficacy of oxygen free radical scavenger compounds in improving small bowel anastomotic healing in ischemia. 50 Sprague-Dawley rats underwent laparotomy and were divided into groups: I. sham operation; II. ischemia produced by ligation of mesenteric vessels along 3-5 cm of bowel; III. bowel transection and anastomosis; IV. ligation of vessels with bowel transection and anastomosis; V. ligation of vessels, bowel transection and IV administration of superoxide dismutase (SOD) (5000 U/kg) prior to anastomosis. All surviving animals were sacrificed after 2 weeks. Anastomotic tensile strength and histology were evaluated. Percent survival and the average length of survival for all groups is seen in the table below. (table: see text) A significant decrease in survival was present with the anastomotic group and the ischemic anastomotic group when compared with controls. An improved survival similar to ischemia alone was present in SOD group. No significant difference was noted between SOD and control groups. The results of this study indicate an improved survival rate and length of survival similar to controls in animals undergoing ischemic and penetrating injury to the bowel with the use of oxygen free radical scavenger compounds prior to anastomosis.