Hemodynamically-efficient graft design for endovascular repair in type B aortic dissection

Aortic dissection (AD) is a catastrophic cardiovascular event that is associated with considerable mortality. AD occurs as a result of a tear in the aortic wall, permitting blood to track within the aortic media layer under arterial pressure, separating the aorta into two separate lumens: the True Lumen (TL) and the False Lumen (FL). Current treatment for AD is medical anti-impluse therapy followed by thoracic endovascular aortic repair (TEVAR) to cover the proximal entry tear and induce FL thrombosis in order to decrease the risk of aneurysm formation and aortic rupture. However, only limited information on the fluid dynamics in dissected aortas after TEVAR has been reported in the literature. In this study, we used a computational approach employing a fluid-structure Interaction Lattice-Boltzmann method coupled with the Immersed Boundary technique to model various graft lengths and flow conditions. Results demonstrate a trend towards increased FL flow reversal as the graft length increases but also increased left ventricular workload, which can ultimately lead to heart failure. These finding suggest that there may exist an optimum graft length that can lead to improved long-term clinical outcomes.