S URGICAL repair of an ascending aortic aneurysm involving the aortic root presents a challenge for the surgeon, anesthesiologist, and perfusionist. Hemorrhage is an important indicator for mortality after repair of annuloaortic ectasia, l?and when a patient refuses all blood products, complications of hemorrhage would likely increase the risks. Hemorrhage during repair of aortic root aneurysm can be caused by the surgical anastomoses, systemic heparinizatlon, exposure to the cardlopulmonary bypass (CPB) circuit, or the prosthetic graft itself) The impairment in hemostasls associated with CPB remains unclear but hkely involves a combination of a reduction m platelet adhesiveness, complement achvation, kaltikrein/ klnin activation, a sUmulation of the fibrinolytic system, and dilution. 4 Aprotmin, a serine protease inhibitor, has been shown to preserve platelet adhesive receptors (Gplb), inhabit contact activation of the kallikrein system, and inhibit plasmin-lnduced fibrmolysIs. When used in conjunction with heparln, aprotinin prevents thrombln formation through inhibmon of the intrinsic clotting cascade. 5 The effectiveness of aprotmin in reducing perloperative blood loss and amount of transfused blood products during cardiac surgery has been demonstrated. T M The combinanon of heparin-bonded perfusion systems and reduced systemic heparinlzation for CPB has been reported 12-i4 Reported advantages of heparin-bonded perfusion systems include reduced actwation of the complement and coagulation systems and improved platelet function caused by the Improved blocompatibility of a heparin-bonded material, both leading to reduced penoperatlve bleeding. 13-16 A drawback in the use of a heparinbonded system is that because of the continuous air-toblood interface associated with roller pump suction, shed mediastlnal blood and vented blood must be returned to a cell-saving device for washing instead of directly into the CPB circuit. In cases involving extensive suctlonmng and venting and excessive surgical bleeding, washing and autotransfusion of suctioned blood may result in a tremendous loss of plasma and platelets, negating the benefits of reduced systemic heparinlzation. Because of this patient's religious behefs, and the nature of her disease process, a heparin-bonded perfusion system for CPB was used in conjunction with full systemic heparinlzatlon and aprotinln administration.