Ancrod vs. Heparin: The Resulting Effect on Oxygenator Performance During Routine Cardiopulmonary Bypass

Ancrod, a thrombin-like enzyme with anticoagulant properties, is extracted from the venom of the Malayan Pit Viper (Agkistron rhodostoma). Recently, Ancrod has been proposed as an alternate anticoagulant for cardiopulmonary bypass (CPB). In order to investigate the effect of Ancrod on the performance of the semi-porous hollow fiber membrane oxygenator now in use during CPB, in-line pressure measurements (pre- and post-oxygenator) and blood gas analysts were carried out in a clinical setting. A control group of 20 patients scheduled for coronary artery bypass grafts were coagulated with heparin and a study group of 20 patients underwent controlled defibrinogenation with Ancrod. There were no significant differences between groups with respect to blood gas values (pO2, PCO2) or pressure gradients across the membrane oxygenator and in all cases the intra-operative course was uneventful. Comparison of electron micrographs from various surfaces of the CPB circuit demonstrated less cellular and proteinaceous material were deposited on the study group's circuits than those of the patients anticoagulated with heparin. This study confirms the efficacy of Ancrod as an alternate anticoagulant for CPB