LONG-TERM IN-VIVO LEFT-VENTRICULAR ASSIST DEVICE STUDY WITH A TITANIUM CENTRIFUGAL PUMP

A totally implantable centrifugal artificial heart has been developed. The plastic prototype, Gyro PI 601, passed 2 day hemodynamic tests as a functional total artificial heart, 2 week screening tests for antit hrombogenicity, and 1 month system feasibility. Based on these results , a metallic prototype, Gyro PI 702, was subjected to in vivo left ven tricular assist device (LVAD) studies. The pump system employed the Gy ro P1 702, which has the same inner dimensions and the same characteri stics as the Gyro PI 601, including an eccentric inlet port, a double pivot bearing system, and a magnet coupling system. The P1 702 is driv en with the Vienna DC brushless motor actuator. For the in vivo LVAD s tudy, the pump actuator package was implanted in the preperitoneal spa ce in two calves, from the left ventricular apex to the descending aor ta. Case 1 achieved greater than 9 month survival without any complica tions, at an average flow rate of 6.6 L/min with 10.2 W input power. C ase 2 was killed early due to the excessive growth of the calf, which caused functional obstruction of the inlet port. There was no blood cl ot inside the pump. During these periods, neither case exhibited any p hysiologic abnormalities. The PI 702 pump gives excellent results as a long-term implantable LVAD.