CARD15: Intra-Cardiac Endograft: a Novel Platform for Continuous Flow Right Ventricular Assist Devices

Purpose: To develop a stable platform for continuous flow RVAD usage that resists suction events and avoids complexities of pump positioning, a feasibility study was undertaken using intra-cardiac endograft stenting. Methods: Using a calf-model on full cardiopulmonary bypass, a covered endograft (36x32x160 mm, Medtronic Valient) was deployed from the right atrial appendage to the inferior vena cava at the diaphragmatic hiatus. A continuous flow centrifugal ventricular assist device (Heartware, Medtronic) was then attached to the right atrial appendage and into the endograft lumen using the VAD’s standard sewing cuff. The RVAD outflow graft was connected to the pulmonary trunk. The calf was separated from cardiopulmonary bypass and the RVAD was increased to maximal speed of 4000 rpms. Heparin was fully reversed with protamine. Assessments with fluroscopy and echocardiography were performed. The animal was supported on the device for 2 hours after which it was humanely euthanized and necropsy performed. Results: Maximal flows of 8 liters/min were achieved thru the RVAD after the animal was separated from cardiopulmonary bypass. There were no suction effects experienced by the RVAD at maximal flow. Fluoroscopy demonstrated maintenance of stent conformation without suction deformation and secure fixation at the inferior vena cava. Epicardial surface echocardiography demonstrated right atrial blood return from the superior vena cava continues to flow unobstructed through the tricuspid valve. On necropsy there was no evidence of thrombus formation within the endograft stent. Summary: Use of an intra-cardiac endograft in the right atrium provided a platform for continuous flow RVAD usage in a calfmodel that was easy to deploy, resisted suction at high flows and maintained appropriate positioning of the pump. Distal stent fixation at the inferior vena cava diaphragmatic hiatus should be considered for determination of stent diameter. Figure 1. Schematic of endograft deployed in right atrium with continuous-flow RVAD