Influence of prosthesis design on hemodynamics in transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is a minimally invasive approach for the treatment of aortic stenosis in patients with a high risk of postoperative complica-tions who are not candidates for open surgery operation. Despite the rapidly growing number of such operations, they have a number of complications with limited choice of parameters and types of implants that do not take into account the individual characteris-tics of the patient. This leads to the question of customization of TAVI implants. The de-velopment of personalized prosthetic designs can reduce the incidence of postoperative complications, such as paravavular regurgitation or damage to the annulus fibrosus, thereby improving patients’ quality of life by optimizing hemodynamic indicators. Thus, the purpose of this study is to numerically simulate the hemodynamic characteristics in the aorta after TAVI to assess the impact of the prosthesis design on its effectiveness. This paper presents eight parametrized prosthesis geometries: two represent models of commercial valves (Evolut R PRO and SAPIEN 3), and the remaining six were developed by the authors. A coupled problem involving fluid-structure interaction was solved. A velocity profile based on echocardiography data was prescribed as the inlet boundary condition at the aorta, while a pressure determined by a two-element Windkessel model was prescribed at the outlet. Based on a comprehensive analysis of the integral parame-ters, three geometries were selected. These geometries demonstrate optimal hemody-namic performance: effective orifice areas exceeding 1.5 cm², moderate pressure gradi-ents (7–12 mmHg), and peak systolic velocities below 2 m/s. Additionally, they exhibit low OSI values (OSI < 0.25), which is indicative of a reduced risk of thrombosis and prema-ture leaflet fatigue. The obtained results provide a basis for the design, engineering, and manufacture of personalized TAVI prostheses that take into account the specific anatomi-cal and physiological features of each patient.