Implantable Rotary Blood Pump Performs as Well as Pulsatile Pneumatic Assist Device

Abstract

A new implantable rotary blood pump (the diagonal pump) was tested. Hemodynamic performance and organ perfusion were analyzed in a heart failure model and compared to the performance of a pulsatile assist device (Medos, Aachen, Germany). Six sheep were instrumented with a. 50 Fr. left atrial inflow cannula and a 16-mm Dacron outflow graft to the descending aorta. After control measurements, left ventricular heart failure was induced by intracoronary injection of microspheres. Measurements were repeated during heart failure, during mechanical support with the Medos device, and during support with the new rotary blood pump. Organ perfusion was analyzed by injection of colored microspheres. Cardiac output, arterial blood pressure, left and right atrial pressure, and first derivative of the left ventricular pressure were all significantly changed during heart failure. These parameters were restored by both types of mechanical support to exactly the same level. Organ perfusion was significantly reduced in all organs during heart failure. There was no difference in organ perfusion with the diagonal pump compared with the pulsatile Medos device. Hemodynamic status and organ perfusion due to left ventricular failure are restored in exactly the same way by a nonpulsatile miniature rotary blood pump and a pneumatic pulsatile assist device (Medos). Rotary blood pumps can be miniaturized and are therefore more attractive than pulsatile displacement pumps for long-term mechanical support.