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 investi gations have reported on the therapeutic utility of topical hydrogels in re ducing the formation of postsurgical adhesions. The goal of the present stu dy is to evaluate the ability of N-O carboxymethylchitosan (a glycosaminogl ycan hydrogel derivative) to reduce the formation of postsurgical pericardi al adhesions in a large-animal model. Sixteen adult New Zealand white rabbi ts were randomly assigned to one of two treatment groups. Group 1 subjects (n = 8) had N-O carboxymethylchitosan directly applied to the heart and ret rosternal 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, blinde d to treatment, graded the formation of pericardial adhesions. The severity of adhesion formation was significantly less in the group treated with NO carboxymethylchitosan (p < .01). This study demonstrates that N-O carboxyme thylchitosan markedly decreases the formation of poststernotomy adhesions i n a large-animal model without untoward cardiac side effects. This hydrogel derivative may prove to be of great therapeutic value when used prophylact ically in the setting of cardiac surgery.