EDN1 and triple-A syndrome: Surprisingly, it was revealed that patients undergoing OSR of ruptured infrarenal AAA with fatal postoperative organ failure have significantly lower levels of endothelin-1 compared to successfully operated and surviving AAA patients. This suggests that elevated circulating endothelin concentrations may also be an acute reaction and safeguarding response to hemorrhagic AAA rupture, with ensuing systemic ischemia and reperfusion.