HEMOLYTIC DIFFERENCES AMONG ARTIFICIAL CARDIAC VALVES USED IN A VENTRICULAR ASSIST PUMP

Ventricular assist devices (VADs) required for cardiac support may pro duce clinically significant hemolysis. VAD valves differ in both mecha nics and hemodynamics. Therefore, we examined a ball valve, a modified tilting disc (MTD) valve, a polyurethane trileaflet valve, and a Bjor k-Shiley monostrut valve to determine their degrees of hemolysis. The valves were tested in a Pierce-Donachy VAD which pumped fresh bovine b lood through a mock loop. Blood samples were analyzed for hematocrit a nd plasma hemoglobin, from which the indices of hemolysis were calcula ted. A one-way analysis of variance indicated significant differences between certain valves. The MTD was the most hemolytic. No significant hemolytic difference was found between the trileaflet and monostrut v alves despite their different designs. The monostrut valve and the MTD valve were hemolytically very different despite their similar design. This study suggests that the valve type significantly affects the hem olysis produced by the VAD.