Effects of intraperitoneal and systemic rapamycin administration on postoperative peritoneal adhesions in rats

Purpose: Consequences and complications of postsurgical adhesions are substantially high. Fearsome complications such as inadverdent enterotomy during reopening of abdomen or bowel obstruction may cause not only morbidity but also mortality. Rapamycin (RAPA) is a carbocyclic, lactone-lactam macrolide antibiotic with immunosuppresive, antitumoral, and antifungal properties. Currently rapamycin has clinical usage in posttransplantation immunosuppression and in coronary and peripheral artery vascular stents on routine basis. Rapamycin has reduced perigraft adhesions in rats after polytetrafluoroethylene (PTFE) graft placement. Immunosuppression has positive effect on postoperative adhesion prevention. We aimed to define and compare systemic and intraperitoneal effect of rapamycin on postoperative peritoneal adhesions.Material and Method: In our study we used male albino-Wistar rats weighing between 300-350g. Three groups, each containing seven rats for intraperitoneal rapamycin, systemic rapamycin, and control groups have been constituted. A peritoneal adhesion model created on each rat. On postoperative 7. day all rats were surgically explored and evaluated with a macroscopic adhesion scoring system by a surgeon who is blinded to the study. In rats which developed adhesions, peritoneal bands excised with affected organs, and in rats with no adhesion, ceacal anterior wall and parietal periton with whole abdominal wall including all layers of except from skin excised for pathologic evaluation.Results: After macroscopic evaluation scores assessed, there were statistically significant difference between three groups (intraperitoneal rapamycin, oral-systemic rapamycin, control)(p=0.002). There were no statistically significant difference between intraperitoneal rapamycin and oral-systemic rapamycin groups(p=0.062). There were statistically significant difference between intraperitoneal rapamycin and control groups(p=0.001). There were no statistically significant difference between oral-systemic rapamycin and control groups(p=0.021).Conclusion: This study showed that in an rat model intraperitoneal rapamycin administration has significant effect on postoperative adhesion preventionKey Words: Postoperative adhesion, intraperitoneal rapamycin, systemic rapamycin