Ischaemia/Reperfusion Contributes to Colonic Injury Following Experimental Aortic Surgery

Abstract Objectives: ischaemia of the colon is an important complication of abdominal aortic aneurysm (AAA) repair. The aim of this animal study was to investigate the effect of sequential ischaemia and reperfusion on sigmoid mucosal pO 2 and its association with local ET-1 release. Material and Methods: twelve pigs underwent colonic ischaemia followed by complete reperfusion. Six other animals were sham controls. A Clark-type microcatheter was used for continuous mucosal pO 2 measurements. Serial systemic and inferior mesenteric vein blood samples were obtained for determination of ET-1 concentration. Neutrophil extravasation was assessed by tissue myeloperoxidase (MPO) activity. Results: arterial occlusion was associated with a gradual decrease of mucosal pO 2 and local release of ET-1. After restoration of blood flow, mucosal pO 2 returned to near baseline values, whereas ET-1 reached its maximum concentration during the reperfusion period. MPO activity was significantly increased. Conclusions: colonic ischaemia and reperfusion causes neutrophil extravasation and local ET-1.