Prevention of pericardial adhesions with N-O carboxymethylchitosan in the rabbit model.

The presence of mediastinal adhesions significantly increases the morbidity and mortality of reoperative cardiac surgical procedures. Previous investigations have reported on the therapeutic utility of topical hydrogels in reducing the formation of postsurgical adhesions. The goal of the present study is to evaluate the ability of N-O carboxymethylchitosan (a glycosaminoglycan hydrogel derivative) to reduce the formation ofpostsurgical pericardial adhesions in a large-animal model. Sixteen adult New Zealand white rabbits were randomly assigned to one of two treatment groups. Group 1 subjects (n = 8) had N-O carboxymethylchitosan directly applied to the heart and retrosternal surfaces after sternotomy was performed, while subjects in group 2 (n = 8) had saline applied to these areas. After a period of 14 days the animals were sacrificed under anesthesia, and independent observers, blinded to treatment, graded the formation of pericardial adhesions. The severity of adhesion formation was significantly less in the group treated with N-O carboxymethylchitosan (p < .01). This study demonstrates that N-O carboxymethylchitosan markedly decreases the formation of poststernotomy adhesions in a large-animal model without untoward cardiac side effects. This hydrogel derivative may prove to be of great therapeutic value when used prophylactically in the setting of cardiac surgery.