Computational analysis of thrombosis risk with variations in left ventricular assist device inflow cannula design in a multi-patient model.

BACKGROUND AND

OBJECTIVES

Left ventricular assist devices (LVADs) are mechanical pumps used to support patients with end-stage heart failure. The inflow cannula is a critical component of the LVAD as it connects the pump to the left ventricle, allowing blood to be drawn from the heart. However, the design of the cannula can significantly impact LV hemodynamics and cause complications, including thrombosis. Therefore, this study aimed to analyze the numerical effects of left ventricle (LV) size on cannula design in order to enhance hemodynamic performance using post-operative left ventricular assist device (LVAD) models.

METHODS

A parametric design evaluation of two different inflow cannulas were carried out on left ventricles (LV) of varying sizes (ranging from 154 to 430 ml) constructed from computerized tomography (CT) data from VAD patients using computational fluid dynamics (CFD) simulations. The study analyzed three key factors contributing to thrombosis formation: blood residence time, blood stagnation ratio, and wall shear stress.

RESULTS

Results showed higher blood residence time and stagnation ratio for larger left ventricular sizes. In addition, increasing the insertion length of the cannula reduced the average wall shear stress.

CONCLUSION

Overall, the study's findings suggest that the optimal cannula shape for LVADs varies with left ventricular size.