Endothelin-1 (ET-1) levels in a porcine model of suprarenal and infrarenal aortic balloon occlusion

Introduction: Aortic cross-clamping, required during conventional abdominal aortic aneurysm (AAA) repair causes decreased blood flow to various organs. The site cross clamping determines the organs affected. The resulting ischemic tissue injury leads to endogenously produced chemical mediators. Aortic aneurysm repair is often accompanied by severe end organ injury. The purpose of this study is to measure ET-1 production in a porcine model of suprarenal and infrarenal aortic balloon occlusion and reperfusion. Methods: 12 intubated and anesthetized Yorkshire pigs were randomly assigned to one of three study groups: control (C), suprarenal (above the celiac axis) (SR), and infra-renal (IR) occlusion. An 8F balloon catheter was inserted into the abdominal aorta via the left femoral artery. After instrumentation, the SR and IR groups had the aorta occluded by inflating the balloon for 45 minutes and then deflating it to restore flow. Data were collected at baseline, after 45 minutes of ischemia and after 5 and 60 minutes of reperfusion. ET-1 was measured by ELISA Results. Values expressed as mean±SD in pg/ml.*p<0.05 vs control (Figure Presented) Conclusions. Serum ET-1 levels were significantly higher following 45 minutes of ischemia in the suprarenal group which returned to baseline following reperfusion. ET-1 plays an important role in maintaining blood pressure as part of the normal stress response. The greater stress of suprarenal aortic surgery leads to an increase in ET-1 levels which may play a role in post-operative complications by causing vasoconstriction with resultant tissue ischemia.