Early demonstration of postoperative adhesions in a rodent model

Objective: To assess the cellular and molecular mechanisms of postoperative adhesion development in a rodent model. Design: Prospective randomized controlled study. Setting: Research laboratory. Patients: Thirty sexually mature female Sprague-Dawley rats. Interventions: Cecal abrasion. Main outcome measure(s): At 0, 2, 4, 8, 16, 24, 48, 72, 96, 168, 336, and 504 hours after cecal abrasion, one to three rats were sacrificed (n = 26). Four nonabraded rats served as controls. Peritoneal adhesion status was evaluated and tissue was collected for histologic and immunohistochemical investigation. Results: Postoperative tissue attachments were identified as early as 2 hours after cecal abrasion. Significant local edema and vessel congestion appeared within 2 hours, and cellular proliferation was observed at 24 hours; angiogenesis and tissue proliferation remained present at 2 weeks. β1 integrin was highly expressed early and was thereafter decreased. Cellular fibronectin was not detectable until 1 week after cecal abrasion. Conclusions: Postoperative adhesions are initiated as rapidly as 2 hours after surgical intervention in this rodent model.