Hemodynamic effects of intra- and supra- deployment locations for a bioprosthetic aortic valve

TL;DR

This study uses patient-specific simulations to compare intra-annular and supra-annular bioprosthetic aortic valve placements, revealing that supra-annular positioning improves hemodynamic performance and reduces blood damage risk.

Contribution

It provides a controlled, patient-specific computational analysis of how valve placement affects hemodynamics, which was not previously done in a single patient model.

Findings

Supra-annular placement results in lower pressure gradients.

Supra-annular placement yields larger effective orifice area.

Reduced hemolysis risk in supra-annular configuration.

Abstract

Aortic valve replacement is a key surgical procedure for treating aortic valve pathologies, such as stenosis and regurgitation. The precise placement of the prosthetic valve relative to the native aortic annulus plays a critical role in the post-operative hemodynamics. This study investigates how the positioning of a biological prosthetic valve -- either intra-annular (within the native annulus) or supra-annular (slightly downstream, in the widened portion of the aortic root) -- affects cardiac fluid dynamics. Using high-fidelity numerical simulations on a patient-specific left heart model derived from CT imaging, we simulate physiological flow conditions to isolate the impact of valve placement. Unlike previous clinical studies that compare different patients and valve models, our approach evaluates the same valve in both positions within a single virtual patient, ensuring a controlled comparison. Key hemodynamic parameters are assessed, including transvalvular pressure drop, effective orifice area, wall shear stress, and hemolysis. Results reveal that supra-annular implantation offers significant advantages: lower pressure gradients, larger orifice area, and reduced shear-induced stress. Furthermore, hemolysis analysis using advanced red blood cell stress models indicates a decreased risk of blood damage in the supra-annular configuration. These findings offer valuable insights to guide valve selection and implantation strategies, ultimately supporting improved patient outcomes.