Assessment of intraperitoneal adhesion formation in a rat model: can a procoagulant substance prevent adhesions?

Previous studies have shown oxidized cellulose to decrease adhesion formation in rats. A recent report showed a decrease in adhesions after application of a fibrin sealant containing thrombin, fibrinogen, and aprotinin, raising the question of whether procoagulants block adhesions by something other than a mechanical barrier effect. To assess the value of a procoagulant in preventing adhesion formation, we compared the efficacy of thrombin with that of oxidized cellulose in decreasing postoperative adhesions in rats. Eighty-five Sprague-Dawley rats underwent midline abdominal incisions and subsequent removal of a small area of right anterior abdominal wall peritoneum. Defects were left open or were closed with interrupted sutures and then treated with thrombin, oxidized cellulose, or nothing. Results obtained at postmortem seven days later showed a decrease in adhesion number and severity among animals treated with oxidized cellulose. No such effect was noted in the thrombin group. No treatment increased adhesion formation. We conclude that although oxidized cellulose appears to be of some benefit in decreasing postoperative adhesion formation in the rat, thrombin alone shows no similar effect. Further conclusions regarding adhesion induction, histologic correlates of adhesion formation, and validity of some methods of adhesion analysis are also addressed.