761 Two CircuLite Pumps as Bi-Ventricular Assist Device (BVAD) in an Ovine Animal Model

Abstract

Purpose: The purpose of this study was to investigate the use of two CircuLite micro-pumps for full biventricular assist in sheep. We therefore examined right and left sided hemodynamic parameters over a range of right and left sided pump speeds. Methods and Materials: Five juvenile sheep (mean-weight 43kg) were implanted with CircuLite pumps in the RV and the LV through a median sternotomy. The RVAD outflow graft was anastomosed end-to-side to the pulmonary artery, and the LVAD outflow to the ascending aorta. After surgical implantation of both pumps we induced ventricular fibrillation and hemodynamic changes were measured using nine different levels of RVAD pump speed (from 20-28k rpm at 1k increments) while the speed of the LVAD was set constant at 24k, then at 26k and finally at 28k rpm. Results: Average results from the 5 sheep with LVAD speed fixed at 24K are shown in the Figure. At any given LVAD speed, both RVAD and LVAD flow increased identically as RVAD speed was increased. Results were similar with LVAD set at the higher speeds. At the highest LVAD and RVAD speeds, flow averaged 3.1 0.7 L/min, and pressures in the right atrium, pulmonary artery, left atrium and aorta averaged 2.2 3.7, 24.4 6.5, 22.4 5.5, and 56.6 8.5 mmHg, respectively. Conclusions: Biventricular assist with the two CircuLite pumps is feasible and able to provide full hemodynamic support in sheep. This approach holds promise for providing biventricular partial support in humans and, in particular, for full support in small adults and children.