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.

Key Words: Postoperative adhesions, angiogenesis, beta 1 integrin, fibronectin