P75: In Vivo Evaluation of a Paracorporeal Pulsatile Ventricular Assist Device in an Ovine Model

Abstract

Background: Ventricular assist devices (VAD) have undergone numerous changes and improvements since their conception. One of the most notable advances was the paradigm change from pulsatile to non-pulsatile, continuous-flow (CF) rotary pumps, which are smaller and more durable. Despite these improvements, the price of CF-VADs makes them challenging to access in developing countries. Hence, an easily implantable, cost-effective VAD has the potential to increase access to life-saving procedures around the world. In this study, we performed two 30-day experiments to assess the safety and durability of the final version of the Vitalmex Paracorporeal Pulsatile Ventricular Assist Device (PPVAD). Methods: The device was implanted in two healthy sheep for 31 and 32 days. Implantation was performed by inserting the inflow cannula into the left ventricular apex and suturing the outflow graft to the descending aorta. Hemodynamic data, such as VAD pulse rate, flow, and pressures, were recorded. Bloodwork, including chemistry, hematology/coagulation profile, and plasma-free hemoglobin, was taken. A necropsy was performed at the end of the study. Values are reported as means with standard deviations. Results: Both animals reached the intended endpoint without any unexpected device-related problems. A fixed VAD rate of 65 bpm was maintained throughout most of the study duration. The average VAD flow was 3.14 ± 0.9 L/min. Plasma-free hemoglobin values were 10.15 ± 3.95 mg/dL. The histopathologic evaluation reported interstitial nephritis and mild cortical fibrosis of the adrenal glands. Thromboembolic incidents were observed in the liver and lungs; these were not clinically significant. The tissue changes surrounding the implant site at the left ventricle and descending aorta were within the expected degree of inflammation and fibrosis. Conclusion: The PPVAD can provide safe pulsatile mechanical circulatory support for 30 days. This device can offer an easily implantable, cost-effective alternative to currently available VADs.