Brief communications Aprotinin and aortic cannula thrombosis

Abstract

Aprotinin has been advocated to reduce perioperative blood loss in patients undergoing cardiopulmonary bypass (CPB).I, 2 Its effect on the coagulation cascade has been investigated by many researchers and its clinical effectiveness has been documented. 3'4 However, the potential adverse sequelae of potent antifibrinolytic therapy has received less attention. Thrombus formation has been reported with pulmonary artery catheters after aprotinin administration. 5 Thrombus formation in the aortic outflow cannula, reported herein, represents a unique complication of antifibrinolytic therapy and merits attention. Case report. A 64-year-old woman weighing 78 kg, with end-stage congestive cardiomyopathy, underwent cardiac transplantation. Two million kallikrein inactivator units (FdU) of aprotinin was bolused intravenously before the initial skin incision, followed by a continuous infusion at 500,000 KIU/hr. Additionally, another 2 million KIU of aprotinin was added to the extracorporeal circuit as a priming dose before institution of CPB. Before CPB, heparin (4 mg/kg) was administered and an activated clotting time (ACT) of 600 seconds obtained. (ACT was measured in celite test tubes in an automated device [Hemochron, International Technidyne Corp., Edison, N.J.]. ACTs during CPB ranged between 600 and 963 seconds.) After implantation of an 18-year-old donor heart, the patient had cardiac graft dysfunction resulting in cardiogenic shock and hypotension. Mechanical support with intraaortic balloon counterpulsation and aggressive inotropic support were instituted. The patient was weaned from CPB and protamine was administered. After decannulation and observation in the operating room for 4 hours, the patient's cardiac hcmodynamics worsened. She was therefore reheparinized (4 mg/kg) and, with the aid of CPB, ABIOMED BVS 5000 (ABIOMED Cardiovascular, Inc., Danvers, Mass.) biventricular assist devices (BVADs) were inserted. A new extracorporeal circuit and new cannulas were used. Aprotinin was not rebolused or added to the prime of the new CPB circuit,