Does sildenafil reverse the adverse effects of ischemia on ischemic colon anastomosis: Yes, 'no'

Introduction: Sildenafil may lead an improvement in anastomotic healing of ischemic left colon anastomosis. Methods: Thirty-six male Wistar albino rats were randomized into four experimental groups (n = 9 in each group). In group 1, a well-perfused left colonic segment was transected, and free ends were anatomosed. In groups 2, 3 and 4 animals underwent a standardized surgical procedure to induce ischemic left colon anastomosis. Group 2 animals received only tap water. In groups 3 and 4 animals received 10 mg/kg/body-weight and 20 mg/kg/body-weight sildenafil, single dose a day during 4 days, respectively. Rats were sacrificed on day 4 following operation. Anastomotic integrity, intra-peritoneal adhesion scores, anastomotic bursting pressures and tissue hydroxyproline levels were recorded. Histopathological examination of the anastomosis was also performed. Results: There was no statistically significant difference among groups with respect to anastomotic integrity (p = 0.142) but ischemia decreased the anastomotic bursting pressure. The mean bursting pressure values were 78.8 ± 24.1, 43.3 ± 26, 55.1 ± 32.4, and 43.3 ± 20.4 in groups 1, 2, 3, and 4, respectively. Group 1 had the highest values whereas; there was no statistically significant difference between groups 1 and 3. There was no statistically significant difference among groups 2, 3, and 4 with respect to tissue hydroxyproline levels, adhesion scores and the Chiu scores. The highest inflammatory cell presence in the granulation tissue was detected in group 2, whereas the lowest was detected in group 4 (p = 0.0001). The highest fibroblast infiltration in the granulation tissue was detected in group 1 (p = 0.045). Discussion: Our results showed that 10 mg/kg sildenafil decreased the adverse effects of ischemia on the healing of ischemic left colon anastomosis. Additional investigations are needed to confirm the effects of phosphodiesterase-5 inhibitors in ischemic colon anastomosis models. © 2008 Surgical Associates Ltd