PREVENTION OF TISSUE-INJURY AND POSTSURGICAL ADHESIONS BY PRECOATING TISSUES WITH HYALURONIC-ACID SOLUTIONS

The effectiveness of inhibiting serosal tissue damage and preventing s urgical adhesions by precoating tissues with dilute solutions of hyalu ronic acid (I was evaluated in a rat cecal abrasion model. This study was performed at three independent laboratories using the same protoco l. Three hundred and seventy-five adult rats were divided into five tr eatment groups (125 animals at each study site): 0.1% HA, 0.25% HA, 0. 4% HA, phosphate-buffered saline solution (PBS), and no solution. The abdominal cavity of each animal was precoated with 4 ml of test soluti on or no solution, prior to a controlled abrasion of the cecum. One we ek later, the animals were sacrificed and adhesions were scored on a 0 -4 scale. The data were pooled because no statistical difference was f ound in the trends at the three study sites. The PBS precoating and no tissue precoating treatment groups had the same high incidence of cec al adhesions, which was significantly higher than the incidence of adh esions in the HA treatment groups. As the HA concentration in the prec oating solution increased from 0% (PBS group) to 0.4% HA, the mean inc idence of cecal adhesions decreased in a concentration-dependent manne r from 1.6 +/- 0.11 to 0.7 +/- 0.09 (P < 0.001). The percentage of ani mals with no cecal adhesions increased from 11% in the PBS group to 50 % in the 0.4% HA treatment group (P < 0.001). In a separate histologic al study employing 150 rats, HA solutions significantly inhibited sero sal tissue damage and ameliorated the inflammatory response due to abr asion and desiccation compared to that with no coating or precoating w ith buffered saline. Together, these studies demonstrate that tissue p recoating with dilute HA solutions reduces damage to serosal tissues d uring surgery and thereby limits formation of postsurgical adhesions. (C) 1995 Academic Press, Inc.