Vascular Aneurysm

Ischemia and reperfusion (I/R) injury during abdominal aortic aneurysm (AAA) repair is inevitable and may lead to postoperative multi-organ failure. Remote ischemic preconditioning (short periods of ischemia in anticipation of longer period of ischemia) may act protectively against ischemia. Studies of ischemic preconditioning in patients with AAA are conflicting. Obstructive sleep apnea (OSA) is a sleep disordered breathing syndrome which may have a protective effect against ischemia. The investigators hypothesize that I/R injury will be less pronounced in patients who have OSA and that the extent of I/R injury will inversely correlate with OSA severity. Accordingly, the aim of this study is to compare postoperative complications and markers of I/R in patients undergoing elective AAA repair who do and do not have OSA.