MINIATURE AXIAL-FLOW PUMP FOR VENTRICULAR ASSISTANCE IN CHILDREN AND SMALL ADULTS

We investigated the efficacy of the Jarvik 2000 intraventricular assis t device (Jarvik Research, Inc., New York, N.Y.) in an ovine model. Th e device is an axial flow pump measuring 1.8 cm in diameter by 5 cm lo ng, has a displacement volume of 12 ml, and can deliver flow from 2 to 7 L/min. Seven devices were implanted through a left thoracotomy into the left ventricle with an outflow graft to the descending aorta. Ani mals were treated with warfarin sodium and aspirin to maintain prothro mbin times approximately 1.5 times control. Animals were followed up f or 3 to 123 days. Two animals died of operative complications at days 3 and 5. One device failed at 58 days because of thrombus formation at the inflow side of the impeller. The remaining four animals were kill ed at days 19, 42, 42, and 123, respectively, because of broken electr ic power cables. Hematocrit values rose significantly higher than preo perative levels (22.8% +/- 3.8% to 30.5% +/- 3.4%); premortem elevatio ns of values higher than baseline values of plasma free hemoglobin (10 .4 +/- 7.8 mg/dl to 17.1 +/- 7.4 mg/dl) and lactate dehydrogenase (391 .5 +/- 113.7 units/L to 771.2 +/- 370.8 units/L) were statistically in significant. Serum creatinine and bilirubin levels were normal. No end -organ dysfunction arising from long-term support was evident clinical ly or at postmortem examination, nor was there any evidence of embolis m or damage to intracardiac structures. We found the Jarvik 2000 intra ventricular assist device to be easily implantable, safe, nonhemolytic , and able to provide physiologic how with power requirements under 10 watts.