Tumor necrosis factor-alpha: a marker for peritoneal adhesion formation

This study investigates the possible correlation between higher levels of tumor necrosis factor-alpha (TNF-alpha) and higher rates of adhesion formation following standard bowel injury. Forty-five Sprague-Dawley rats were divided into three equal groups. Blood was obtained from all rats preoperatively. All rats were subjected to a laparotomy. In group 1 the peritoneal cavity was irrigated with normal saline. In group 2 the cecal serosa was abraded, while rats in group 3 had 2 cm of their small bowel resected. A peritoneal catheter was placed in all rats prior to closure. Blood samples were obtained at 30, 90, and 180 min following injury. Peritoneal exudate (PE) was collected and the catheter removed in 3 hr. Blood samples and peritoneal exudate were processed and levels of TNF-alpha were determined. The severity of adhesions was graded 3 weeks postoperatively using a score of 0 (absent) to III (extensive, dense). Histological evaluation for collagen deposition and fibroblasts was carried out. Rats in group 1 had significantly lower adhesion grades when compared to groups 2 and 3 (grade 0; P < 0.0001). Postoperatively, groups 2 and 3 had higher serum and PE TNF-alpha levels when compared with group 1 (P < 0.01). There was a significant correlation between higher grades of adhesions and higher levels of serum and PE at 30, 90, and 180 min following operation (P < 0.01 and < 0.05, respectively). TNF-alpha, a proinflammatory cytokine, appears to be a good biological marker for postoperative intraabdominal adhesion formation.