Effects of Oral Zafirlukast, Sildenafil, or Pirfenidone on the Formation of Postsurgical Intra-abdominal Adhesions in an Experimental Rat Model.

Introduction: Intra-abdominal adhesions' main etiology is surgical procedures that commonly require reintervention. Oral treatments with Sildenafil, Zafirlukast, and Pirfenidone have yielded decreased severity of fibrotic phenomena secondary to the introduction of foreign material. This study aimed to evaluate the efficacy of oral Zafirlukast, Sildenafil or Pirfenidone treatment on reducing or preventing intra-abdominal adhesions in an experimental rat model. Methods: Four groups, each of 10 male Wistar rats weighing 250–300 g, were used. A midline laparotomy was used to excise an area of 1.5´1.5cm and reconstructed with polypropylene mesh fixed to the abdominal wall. After 12 h, oral doses of Zafirlukast (1.25 mg/kg, group B), Sildenafil (15 mg/kg, group C), or Pirfenidone (500 mg/kg, group D) were given every day for eight days. The control group, A, received no treatment. At day nine, animals were reoperated. The implant was resected after ethically approved euthanasia and specimens were fixed in 10% formaldehyde for histopathology. Results: Control group A yielded adhesions with greater fibrovascular density and neighboring organ involvement than the other groups (P = 0.001), as well as intense inflammatory infiltrates and numerous granulomas (P = 0.04). Adhesions in group C had less fibrovascular density (P = 0.03) with decreased serosal injuries (P = 0.001) and less organ involvement. Group D had reduced adhesions without organ involvement (P < 0.01), and less inflammatory infiltrates, collagen fibers, and foreign body granulomas than groups B or C (P < 0.01). Conclusions: Oral administration of these agents did not prevent adhesions but ameliorated them. Oral Pirfenidone offered the best performance and could be recommended for human use.