P17: “Vadoscopy” Of Universal Ventricular Assist Device Shut-Off Feature During Pump Operation

Abstract

Objective: The automatic, universal ventricular assist device has been designed for biventricular support (RVAD or LVAD). Device architecture (UVAD, Fig. 1A, B) enables a life-saving automatic forward flow shut-off function that, in the event of power interruption, helps mitigate patient hazard. Herein, we report the endoscopic visualization (“vadoscopy”) approach used to directly observe the UVAD shut-off function during device activation. Methods: The UVAD implanted in an ex vivo model and connected to a mock circulatory loop was used to simulate pump performance conditions. Device insertions in RVAD and LVAD positions were individually tested. The endoscopic visualization (Karl Storz 5 mm, 30° endoscope; Olympus CH-S190-XZ-E/Q Full HD 3CCD Camera) of the pump rotor occurred during operation and shut-off. The endoscope was placed through left and right atrial appendage and secured with a purse-string, respectively for UVAD used for left (LVAD) and right ventricular (RVAD) support. Results: The circulatory mock loop and ex vivo heart circulation were successfully maintained for both RVAD and LVAD settings. Endoscope was introduced through hermetically sealed insertion point. Direct visualization of the moving UVAD rotor was achieved at various modulated speeds and flows (continuous and pulsatile). The visual confirmation of sub-optimal and full rotor shut-off function (complete closure) was obtained in RVAD and LVAD conditions (Fig. 1C, D, E, F). Conclusion: The UVAD aperture mechanism enabled optimal forward flow shut-off in continuous and pulsatile speed and flow modulation. Direct endoscopic visualization of the UVAD with moving rotor has been feasible. Additional device feature assessment is ongoing.Figure 1. A - UVAD with open aperture; B - UVAD closed aperture; C - Rotor view via inflow; D - Rotor at nominal speed; E - Simulated sub-optimal rotor closure with large gap and regurgitant flow; F - Full rotor shut-off (nearly zero flow) through aperture area.