Journal Article

Effect of Sinotubular Junction Size on TAVR Leaflet Thrombosis: A Fluid–Structure Interaction Analysis

Houzeaux, Guillaume, Samaniego, Cristóbal, Bluestein, Danny, Reza, Symon, Vázquez, Mariano, Kovarovic, Brandon, Oks, David

2024

Overview

TAVR has emerged as a standard approach for treating severe aortic stenosis patients. However, it is associated with several clinical complications, including subclinical leaflet thrombosis characterized by Hypoattenuated Leaflet Thickening (HALT). A rigorous analysis of TAVR device thrombogenicity considering anatomical variations is essential for estimating this risk. Clinicians use the Sinotubular Junction (STJ) diameter for TAVR sizing, but there is a paucity of research on its influence on TAVR devices thrombogenicity. A Medtronic Evolut® TAVR device was deployed in three patient models with varying STJ diameters (26, 30, and 34 mm) to evaluate its impact on post-deployment hemodynamics and thrombogenicity, employing a novel computational framework combining prosthesis deployment and fluid-structure interaction analysis. The 30 mm STJ patient case exhibited the best hemodynamic performance: 5.94 mmHg mean transvalvular pressure gradient (TPG), 2.64 cm 2 mean geometric orifice area (GOA), and the lowest mean residence time (T R )—indicating a reduced thrombogenic risk; 26 mm STJ exhibited a 10 % reduction in GOA and a 35% increase in mean TPG compared to the 30 mm STJ; 34 mm STJ depicted hemodynamics comparable to the 30 mm STJ, but with a 6% increase in T R and elevated platelet stress accumulation. A smaller STJ size impairs adequate expansion of the TAVR stent, which may lead to suboptimal hemodynamic performance. Conversely, a larger STJ size marginally enhances the hemodynamic performance but increases the risk of TAVR leaflet thrombosis. Such analysis can aid pre-procedural planning and minimize the risk of TAVR leaflet thrombosis.

• Publisher: Springer International Publishing,Springer Nature B.V
• Subject: Aorta / Aorta, Thoracic / Aortic stenosis / Aortic Valve - surgery / Aortic Valve Stenosis - surgery / Biochemistry / Biological and Medical Physics / Biomedical and Life Sciences / Biomedical Engineering and Bioengineering / Biomedicine / Biophysics / Classical Mechanics / Fluid-structure interaction / Heart Valve Prosthesis - adverse effects / Hemodynamics / Humans / Implants / Orifices / Original Article / Patients / Prostheses / Risk / Risk reduction / Thromboembolism / Thrombosis / Thrombosis - etiology / Transcatheter Aortic Valve Replacement - adverse effects / Treatment Outcome