Antithrombin III prevents deleterious effects of remote ischemia-reperfusion injury on healing of colonic anastomoses

Background: Antithrombin III is known as the most important natural inhibitor of thrombin activity and has been shown to attenuate local harmful effects of ischemia-reperfusion injury in many organs. In recent animal studies, delaying effect of remote organ ischemia-reperfusion injury on healing of intestinal anastomoses has been demonstrated. In this study, we investigated whether antithrombin III reduces deleterious systemic effects of ischemia-reperfusion injury on healing of colonic anastomoses in rats. Methods: Anastomosis of the left colon was performed in 24 rats that were divided into three groups: sham operated control (group I, N = 8), 30 minutes of intestinal ischemia-reperfusion by superior mesenteric artery occlusion (group II, N = 8), antithrombin III treated group (250 U/kg before and after the ischemia-reperfusion, group III, N = 8). On postoperative day 6, all animals were sacrificed, and bursting pressure and tissue hydroxyproline content of the anastomoses were assessed and compared. Results: On postoperative day 6 the mean bursting pressures were 149.6 ± 4.8, 69.8 ± 13.5, and 121.8 ± 8.7 mm Hg for groups I, II, and III, respectively (P = 0.000). Mean tissue hydroxyproline concentration values were 389.5 ± 29.6, 263.1 ± 10.0, and 376.0 ± 33.8 μg/mg for groups I, II, III respectively (P = 0.005). Conclusions: This study showed that, antithrombin III treatment significantly prevented the delaying effect of remote organ ischemia-reperfusion injury on anastomotic healing in the colon. Further clinical studies are needed to clarify whether antithrombin may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where remote organ ischemia-reperfusion injury takes place.