Advances in mathematical modeling have enabled the use of patient-inspired geometries and boundary conditions in numerical simulations of the cardiovascular system to study its diseases. Aortic stenosis (AS) is one of the most common chronic aortic valve disorders, especially in patients with a bicuspid aortic valve (BAV), affecting both blood flow hemodynamics and the structure of the aorta. While aortic valve replacement (AVR) surgery is an accepted treatment for severe cases, it does not eliminate the risk of ascending aorta (AAO) dilation, and reoperation on the aorta may become necessary.

This study investigates how hypothetically reducing the diameter of the AAO could affect blood flow hemodynamic factors and the structural domain using the fluid-structure interaction (FSI) method. The study involves two 3D patient-inspired models of the aorta from BAV patients who have undergone AVR surgery, along with one healthy model. The results show that even after AVR, velocity magnitude, wall shear stress, and von Mises stress are higher in these two cases compared to the control. The maximum von Mises stress in the ascending aorta was found to be 250 kPa in Model 2 and 186 kPa in Model 3, both of which are higher than the control model value of 101 kPa. A 5% reduction in the diameter of the ascending aorta in Model 2 resulted in a 6.5% decrease in von Mises stress. Reducing the diameter of the AAO in these models decreased the systolic maximum von Mises stress across all models, while wall shear stress showed no significant change. The results indicate that replacing the aortic valve does not necessarily restore the hemodynamic conditions of these patients to normal. However, the timing and extent of surgery to repair the ascending aorta in these patients are crucial.