Prevention of postoperative peritoneal adhesions by O-carboxymethyl chitosan in a rat cecal abrasion model

Purpose: Post-surgial adhesion formation can result in significant morbidity and mortality. N,O-carboxymethyl chitosan (N,O-CMC) has been previously shown to be effective in the prevention of postsurgical adhesion formation. In this study, we evaluated the ability of O-carboxymethyl chitosan (O-CMC), another chitosan derivative generated by carboxymethylation of chitosan's oxygen centers, to reduce postsurgical adhesion development. Methods: Twenty male Sprague-Dawley rats (250 ± 20 g) were divided into two equal groups: O-CMC group and saline (control) group. All rats underwent a midline laparotomy and the cecum was abraded to cause petechial hemorrhages. Following peritoneal injections of either saline or O-CMC, the incisions were closed. Seven days after surgery, the animals were killed and adhesion formation was scored. Tissue samples from the adhesions were examined histochemically. Results: Adhesion formation was significantly decreased in the O-CMC group (P < .001) in comparison with the control group. Furthermore, significantly less collagen (P < .001) and fewer inflammatory cells and fibroblasts were detected in the O-CMC-treated animals. Additionally, a significantly (P < .05) lower level of TGF-β1 expression was found in the O-CMC group. Conclusion: O-CMC appears to be effective in the prevention of postoperative peritoneal adhesion formation, which may be attributed to decreased accumulation of inflammatory cells and fibroblasts and reduced collagen synthesis.