Computational fluid dynamics analysis of hemodynamics in bicuspid aortic valve with giant aneurysm

The current study was performed aimed at investigating the impact of bicuspid aortic valve (BAV) with a giant aneurysm of the ascending aorta (AAo) on hemodynamics within the aorta using Computational fluid dynamics (CFD), with an attempt to gain insights into the clinical management strategies based on hemodynamic considerations.

One numerical model of the AAo with BAV (specifically, a left/right cusp fusion type) and a giant aneurysm was constructed using MRI medical images. The aneurysm had a diameter of 10.5 cm. Subsequently, hemodynamics in this model were simulated numerically, and flow patterns and loading distributions were investigated. To understand these characteristics, we applied the CFD method to simulate the hemodynamics and estimate the risk associated with the fully dilated aorta.

The presence of a giant aneurysm significantly influenced and altered hemodynamics within the AAo in this BAV patient case. In our model of a 10.5 cm aneurysm, the BAV-induced eccentric jet impinged on the aortic wall, generating complex, recirculating flow patterns and elevated turbulent kinetic energy within the aneurysmal sac. Hemodynamic parameters were asymmetrically distributed at the aneurysm, and the wall shear stress (WSS) in this aneurysm was pathologically low. These conditions suggest the risk of asymmetric dilation and aortic dissection, and thereafter, the risk of aneurysm rupture was further heightened, especially when the aneurysm reached 10.5 cm in size.

The CFD-based analysis method helped elucidate the biomechanical mechanisms that a BAV may contribute to the development of a giant aneurysm in the AAo, offering valuable insights for treatment strategies in patients with giant aneurysms.