In Vitro Hemocompatibility Evaluation of Modified Rotary Left to Right Ventricular Assist Devices in Pulmonary Flow Conditions

Right ventricular failure is a common postoperative com-plication following left ventricular assist device (LVAD) im-plantation. Left ventricular assist devices are adapted for right ventricular assist device (RVAD) support by reducing the right pump speed or restricting the diameter of the outflow graft by “banding.” We sought to conduct in vitro hemocompatibility testing in a pulmonary flow condition for current modification of an LVAD for RVAD support, with a specific aim to provide benchmark values for future RVAD development. Two Heart-Ware HVADs coupled to custom-built blood circulation loops, as RVADs, were tested using human blood (n = 6). The RVADs were either used in reduced speed (1,920 ± 50 RPM) or band-ing conditions (3,050 ± 50 RPM) to mimic healthy pulmonary circulation hemodynamics. Blood from the loop was sampled at 0, 15, 60, 150, and 300 min to investigate the level of he-molysis, red blood cell (RBC) deformability, and the activation and aggregation of platelets. The amount of hemolysis and RBC deformability were significantly increased with banding compared with reduced speed (p < 0.05). No significant dif-ferences were found between the two conditions for platelet activation and platelet aggregation. In conclusion, we have evaluated the hemocompatibility of the HVAD when used for RVAD support in the clinically used modes of reduced speed and outflow graft banding under a pulmonary flow conditions that are commonly used in the biventricular failure population. We anticipate the benchmark values in the current study will facilitate future RVAD development.