The effect of LVAD cannula anastomosis location on micro-emboli movement in the aorta / 医用生物力学

ABSTRACT

Objective To clarify the influence from left ventricular assist device （LVAD） cannula anastomosis on micro-emboli movement by numerical simulation methods. Methods Firstly, a patient-specific aorta geometric model was reconstructed based on CT scan images of a patient with heart failure. Three geometric models of LVAD support were established according to clinical practice, and the outflow cannula of LVAD was anastomosed at the three different locations of ascending aorta (the anterior wall, between anterior wall and lateral wall, the lateral wall of ascending aorta). Secondly, the computational fluid dynamic (CFD) approach combined with the discrete phase theory was used to calculate the hemodynamic states, and Fluent finite element software was used for numerical simulation of the fluid. Finally, the micro-emboli distribution flow pattern, wall shear stress (WSS) and velocity vector were extracted to evaluate the hemodynamic state. Results The probability of micro-emboli entering the brain vessel at the three different anastomosis locations were 23.6%, 33.8% and 36.7%, respectively. Besides, vortex was observed around the anastomosis locations. Conclusions The different anastomosis locations of LVAD cannula can significantly change the hemodynamic environment, which will influence micro-emboli movement in the aorta. The research findings provide some insights and theoretical support for optimizing the anastomosis to decrease occurrence risk of stroke in clinic.