Fluid-structure interaction simulation of transcatheter aortic valve replacement in a patient with bicuspid aortic valve stenosis and mitral regurgitation

Transcatheter aortic valve replacement (TAVR) is the standard-of-care treatment for high-risk patients and is also approved for intermediate-risk patients with severe aortic stenosis. However, owing to concerns about valve asymmetry resulting in inadequate expansion or apposition, TAVR in patients with bicuspid aortic valves (BAV) is still considered as a contraindication. Moreover, the effect of TAVR in patients with severe mitral regurgitation (MR) is not clear. Our goal is to investigate the hemodynamic variation in a BAV patient under MR before and after TAVR using fluid-structure interaction (FSI) simulations. A previous validated FSI framework that combines smoothed particle hydrodynamics and nonlinear finite element method is adopted. Results from the pre- and post-TAVR FSI simulations are found to be in good agreement with the clinical data, including velocity waveforms, transvalvular pressure drops, and effective orifice areas. A parametric study is performed to examine the impact of TAV deployment position on the cardiac flow. This study is expected to provide mechanistic insights for TAVR in these clinically challenging cases.