 Much of the controversy and many of the conflicting results arise from either inadequate information i.e., the definitive prospective study has not been done, from inadequately powered studies for the intended outcome, inclusion of multi-institution and multi-surgeon outcomes, or from studies involving patients with advanced ischemic heart disease whose ventricular function may have been compromised perioperatively. To overcome the mentioned limitations, and to better characterize to postoperative renal outcomes, we propose to investigate the safety of aprotinin in a single institution, single surgeon, and very large homogenous surgical cohort who underwent surgical repair of the ascending and aortic arch with use of hypothermic CPB. 