The effect of mitomycin and dexamethasone on peritoneal adhesion formation after abdominal surgery in Rat

Introduction: Adhesion formation after abdominal and pelvic surgery is a serious problem which can lead to bowel obstruction and chronic abdominal pain and female infertility. After peritoneal injury, histamine and other vasoactive kinines which secreted from inflammatory cells and fibroblasts induce peritoneal adhesion formation. This study is designed according to the suppressing effect of dexamethasone on inflammatory cells and of mitomycin on fibroblast function. Materials and Methods: This experimental study was done in two stages. In the first stage, 60 rats were randomly divided in 6 groups. After laparatomy, peritoneal washing was done for 3 minutes with saline, mitomycin solutions (0.25mg/cc, 0.5mg/cc and 1mg/cc), dexamethasone (0.3mg/Kg), and dexamethasone (0.3mg/Kg) plus mitomycin (0.5mg/cc). Six weeks later, the second laparatomy was done and the incidence rate and severity of adhesions were evaluated. In the second stage of study, 90 rats in 6 groups were evaluated. The peritoneal cavities were washed with normal saline, mitomycin (0.25mg/Kg, 0.5mg/Kg and 1mg/Kg), dexamethasone (0.3mg/Kg), and mitomycin (0.5 mg/cc) plus dexamethasone (0.3mg/Kg). Then adhesion formation was evaluated same as first stage. Results: The study showed peritoneal washing with 0.25mg/cc, 0.5mg/cc and 1mg/cc of mitomycin solutions caused death of all animals. Mitomycin solutions at doses of 0.5mg/Kg and 1mg/Kg decreased the rate (P