Investigation of Ventricular Assist Device Inflow Cannula Configurations within Single Ventricle Hearts

Abstract

Ventricular assist devices (VADs) are life-saving devices that provide cardiac support to failing hearts. However, over half of VADs are malpositioned which can lead to serious complications such as thrombus formation, pump failure, and even patient death. Therefore, this work investigates the relationship between VAD inflow cannula position and potential for thrombus formation, and proposes a surgical method for minimizing instances of VAD mispositioning within single ventricle hearts.

VADS are commonly implanted in either the diaphragmatic or apical configuration. Both configurations were explored; specifically, the effect of the inflow cannula position on fluid flow within the ventricle chamber was assessed via computational fluid dynamics and validated with particle image velocimetry using a mock circulation loop. A new surgical technique involving low-cost image guided surgery was also investigated and evaluated using computational fluid dynamics to predict thrombogenic potential due to implant positioning.

Computational results revealed a greater volume of fluid with thrombogenic potential for the apical inflow cannula configuration. While particle image velocimetry validated overall trends observed in the computational model, specific numerical values differed, suggesting the need for future refinement of both models. Computational analysis also revealed reduced thrombogenic potential for inflow cannulas implanted using image guided surgery rather than traditional surgical techniques. Accordingly, image guided surgery should be considered as a useful tool for optimizing VAD inflow cannula positioning in complex surgical scenarios such as patients with single systemic ventricles.