Healing of ischemic colonic anastomoses in the rat: role of antibiotic preparation.

In this study we evaluated the relative effects of ischemia with and without antibiotic bowel preparation on colonic wound healing. Thirty-two Sprague-Dawley rats (185 to 300 gm) were divided into five study groups: Groups I and II (n = 14) had no colonic ischemia, half receiving antibiotic bowel preparation before colocolostomy. Groups III, IV, and V (n = 18) had colonic ischemia induced by division of the marginal artery and ligation of the arteries to the splenic flexure and pelvic colon, assuring that all blood supply to the left side of the colon was intramural. Enteral (neomycin and erythromycin) antibiotic preparation was given in group III, no antibiotics were given in group IV, and parenteral (clindamycin and gentamicin) preparation was given in group V. The mid-left side of the colon was transected and an everting anastomosis was constructed with continuous 6.0 silk sutures. All animals were killed on the seventh postoperative day. Anastomotic healing in unprepared, ischemic rat colon was severely impaired, with an 83% dehiscence rate. In the colon prepared with enteral antibiotics, no adverse effect of ischemia was found. No animal had dehiscence, proximal dilation of the colon, or intra-abdominal abscess. This study may have clinical relevance in patients with ischemic intestinal disorders.