Ischaemia/reperfusion contributes to colonic injury following experimentalaortic surgery

Objectives: ischaemia of the colon is an important complication of abdomina l aortic aneurysm (AAA) repair. The aim of this animal study was to investi gate 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 ischaemic followed by c omplete reperfusion. Six other animals were sham controls. A Clark-type mic rocatheter was used for continuous mucosal pO(2) measurements. Serial syste mic and inferior mesenteric vein blood samples were obtained for determinat ion of ET-1 concentration. Neutrophil extravasation was assessed by tissue myeloperoxidase (MPO) activity. Results: arterial occlusion was associated with a gradual decrease of mucos al pO(2) and local release of ET-1. After restoration of blood flow, mucosa l 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 ischaemic and reperfusion causes neutrophil extravasat ion and local ET-1.