LONG-TERM BIVENTRICULAR SUPPORT WITH AN AXIAL FLOW PUMP IN A CALF MODEL

Abstract

Purpose: The continuous-flow Jarvik FlowMaker is used clinically for treating left ventricular (LV) failure. Because simultaneous right ventricular (RV) support sometimes is also necessary, we developed a method for biventricular support and assessed its long-term feasibility in a calf model. Methods: One FlowMaker was implanted in the LV with the outflow graft anastomosed to the descending aorta. The other was implanted in the RV, via the tricuspid valve, affixed to the right atrial appendage with the outflow graft anastomosed to the pulmonary artery (PA) trunk. Hemodynamics were recorded for 30 days. On day 30, before sacrifice, both pumps were operated at varying speeds, the PA was gradually occluded distal and proximal to the anastomotic site, and dual pump efficacy was assessed at various degrees of pulmonary vascular resistance, RV hypertension, global heart failure, and ventricular fibrillation (VF). Results: Hemodynamics remained stable during the 30-day chronic study and no major adverse events occured. During all acute physiologic manipulations, before sacrifice, the cardiac output ranged from 3 to 11 L/min, LVEDP from 11 to 24 mmHg, and CVP from 9 to 25 mmHg. Necropsy was non-remarkable. Conclusion: The dual technique offered stable satisfactory biventricular assistance for 30 days and during the acute hemodynamic manipulations. Additional studies will assess the effects of pulseless perfusion on the pulmonary circulation and develop a single pump-speed controller to coordinate simultaneous dual pump operation.