[Evaluation of postsurgical adhesion prevention using different formulated sodium hyaluronate membranes]

The rat abdominal wall defect and cecal abrasion model was adopted in this study to investigate the anti-adhesion effect of different formulated sodium hyaluronate membranes. Both injured surfaces of abdominal wall and cecum in experiment groups A, B, and C were covered using the corresponding formulated membrane A (composed of sodium hyaluronate and chitosan), membrane B (sodium hyaluronate), and membrane C (composed of sodium hyaluronate and carboxymethyl chitosan), respectively. And no material was used in the surgical as control group. Seven days after the surgery, the grade and score of abdominal adhesion of rats were evaluated according to Phillips' and Nair's classification methods respectively. Then tissue samples were collected and prepared for histological examination. The rank sum tests of scores of adhesion between groups were carried out. It showed that there was no significant difference of adhesion scores among experimental group A and control group (P > 0.05). But the differences were statistically significant (P < 0.01) among group B or C and control group, which indicated the anti-adhesive effect of B formulation and C formulation sodium hyaluronate membranes. The histological examination showed in group A that there was heavy inflammatory cell invasion and necrosis in the newly formed adhesive fibrous tissue, especially in the zone of remaining membrane A. Normal injury healing process was observed in rat abdominal wall and cecal surface covered using membrane B or C. The A formulation sodium hyaluronate membrane had poor biocompatibility which resulted in no anti-adhesion effect. The prevention of adhesion formation by B formulation and C formulation sodium hyaluronate membranes were confirmed in this experiment and would be worthy of further exploitation.