Antibiotic irrigation and the formation of intraabdominal adhesions.

The efficacy of antibiotic peritoneal lavage in the prevention of postoperative infection is controversial. The role of intraperitoneally administered cefazolin and tetracycline in the formation of adhesions was studied in the rodent model. Thirty-two rats were divided into 3 groups. Group 1 underwent midline laparotomy with instillation of 10 ml of normal saline solution. Group 2 and Group 3 underwent the same procedure with instillation of 0.2 percent saline solutions of cefazolin or tetracycline, respectively. Animals were sacrificed after 2 weeks. Intraabdominal adhesions were graded and samples of parietal peritoneum were processed for histologic data. Group 2 and Group 3 had significantly higher adhesion scores compared with Group 1 (p less than 0.001). Histologic appearance of both antibiotic-irrigated groups showed mesothelial thickening with presence of fibroblasts and collagen. Cefazolin and tetracycline irrigation of the abdominal cavity contributes to the formation of peritoneal adhesions in the rat model.