Aprotinin administration and pulmonary thromboembolism during orthotopic liver transplantation: report of two cases.

Abstract

rthotopic liver transplantation (OLT) is the pri- mary curative procedure for patients with end- stage liver disease. This procedure is frequently associated with massive blood loss because of both the nature of the operation and the coagulopathy that accompanies the underlying disorder. Bontempo et al. (1) demonstrated that the quantity of blood transfused during surgery correlates inversely with survival. The use of aprotinin during OLT has been advocated to decrease intraoperative blood loss (2- 4). Other studies have argued against the routine use of aprotinin dur- ing liver transplantation because definite benefits have not been demonstrated (5,6) and complications may occur. Fatal pulmonary thromboembolization during liver transplantation associated with aprotinin administration has been described (7-10). We report two additional cases of pulmonary thromboemboliza- tion in liver transplant patients treated with aprotinin. induction with a test dose of 1 mL (10,000 kallikrein inhib- itory units (KIU)) followed by an initial dose of 1,000,000 KIU over 35 min and then a continuous infusion of 250,000 KIU per hour. Hypotension was noted during the preanhe- patic phase and treated with lactated Ringer's solution, red blood cells, fresh frozen plasma, and phenylephrine. The case proceeded uneventfully and an inferior vena cava (IVC) test clamp was applied. Profound hypotension was noted and treated with clamp removal, fresh frozen plasma, cal- cium chloride, and packed red blood cells with resolution. The test clamp was reapplied and tolerated well. During the anhepatic phase, hypotension recurred resistant to phenyl- ephrine. Norepinephrine was begun and stabilized the blood pressure. The suprahepatic IVC, infrahepatic IVC, and the portal vein anastomoses were completed, and the cross- clamps were released. The blood pressure gradually de- creased followed by the appearance of large v waves on the central venous pressure tracing. The radial arterial pres- sure waveform became nonpulsatile (Fig. 1). Resuscitation was initiated with volume, calcium, epinephrine, and chest compressions. Ventricular tachycardia followed. A sternot- omy was performed, and direct cardiac compressions were initiated. No arterial tracing was observed despite an ade- quately filled right ventricle. Surgical exploration of the right ventricle and pulmonary artery revealed a large formed blood clot in both branches of the pulmonary artery and attached to the valve leaflets. Cardiopulmonary bypass was initiated and the transplant surgery proceeded with completion of the hepatic artery and biliary duct anastomo- sis. Attempts to wean the patient from bypass, including institution of intraaortic balloon counter pulsation, were unsuccessful and resuscitation was terminated. Autopsy re- sults demonstrated bilateral pulmonary thromboemboli with pulmonary hemorrhage involving the left lower, right middle, and right lower lobes. Clot was also noted in the IVC and attached to the valve leaflets on the right side of the heart. Case 2