The impact of balloon-expandable transcatheter aortic valve replacement on concomitant mitral regurgitation: a comprehensive computational analysis

Abstract

<jats:p>The aortic and mitral valves function in a reciprocal interdependent fashion. However, the impact of transcatheter aortic valve replacement (TAVR) on the aortic–mitral continuity and severity of mitral regurgitation (MR) are poorly understood. In this study, a comprehensive engineering analysis was performed to investigate the impact of TAVR on MR severity and left heart dynamics in a retrospective patient case who harbours bicuspid aortic valve stenosis and concomitant functional MR. The TAVR procedure was computer simulated using a balloon-expandable valve, and the impact of three implantation heights on aortic–mitral coupling, MR severity and device performance were analysed. The accuracy and predictability of the computer modelling framework were validated with pre- and post-operative echo data. The highest deployment model resulted in higher stresses in the native leaflets, contact radial force and stent recoil, while the midway implantation model gave better haemodynamic performance and MR reduction in this patient case. Although the regurgitant volume decreased (less than 10%) for the three deployment configurations, no significant differences in MR severity improvement and mitral leaflet tethering were found. Acute improvement in MR was (i) due to the mechanical compression of the stent against the aortic–mitral curtain, (ii) due to an immediate drop in the ventricular pressure and transmitral pressure gradient. Albeit a single real clinical case, it is our hope that such detailed engineering computational analysis could shed light on the underlying biomechanical mechanisms of TAVR impact on MR.</jats:p>

Transapical mitral valve repair with neochordae implantation: FSI analysis of neochordae number and complexity of leaflet prolapse

“…In particular, the effect of neochordae length on postrepair MV dynamics was investigated. However, for physiologically accurate simulations and rigorous evaluation of MV repair treatments, the intraventricular blood dynamics and the structural mechanics of the valves should be modeled together, an area where fluid‐structure interaction (FSI) modeling is required …”

“…However, for physiologically accurate simulations and rigorous evaluation of MV repair treatments, the intraventricular blood dynamics and the structural mechanics of the valves should be modeled together, an area where fluid-structure interaction (FSI) modeling is required. [15][16][17][18] In the present work, we employed a previously developed left heart (LH) FSI model with multiple levels of PML prolapse 19 to simulate transapical neochordae implantation and better understand the biomechanical interaction between the neochordae and the LH structures. Specifically, we assessed the magnitude and time course of the force exchange between the native mitral apparatus, the transapical sutures, and the blood flow under baseline, prerepair, and postrepair states throughout the cardiac cycle.…”

Comparative quantification of primary mitral regurgitation by computer modeling and simulated echocardiography

“…However, several researchers, including our group, have shown that it is a promising method in the field of cardiovascular biomechanics. It has been used to study the mitral valve mechanics (47), left ventricular flow (29), TAVR impact on MR (8), and wall shear stress of abdominal aortic aneurysm (1). Because of the limitations of the Abaqus SPH formulation, the small-scale flow features close to the wall boundary may not be accurately resolved.…”

Fluid–Structure Interaction Analyses of Biological Systems Using Smoothed-Particle Hydrodynamics

“…Subsequently, it was used to assess several diseased mitral valve states [ 43 , 44 , 45 , 46 ] and applications of medical devices designed to correct them [ 47 , 48 , 49 , 50 ]. Besides the mitral valve, other valves have been studied using the same methods [ 42 , 51 , 52 , 53 , 54 , 55 ]. The SPH method has been validated to study the hemodynamics of the left ventricle [ 29 ].…”