Structural simulations of prosthetic tri-leaflet aortic heart valves

Area of Science:

• Biomedical Engineering
• Computational Mechanics
• Materials Science

Background:

• Prosthetic heart valves are crucial for treating aortic valve disease.
• Accurate simulation of polymeric aortic valve (PAV) structural behavior is essential for design optimization.
• Existing models may not fully capture the complex nonlinear dynamics of PAVs.

Purpose of the Study:

• To develop and validate a combined computational and experimental approach for nonlinear structural simulations of PAVs.
• To assess the accuracy of finite-element (FE) models in predicting PAV kinematics.
• To introduce novel quantitative metrics for evaluating PAV deformation.

Main Methods:

• Generation of nonlinear shell-based and quasi-static FE structural models for PAVs, including leaflets, stents, and root materials.
• Application of ensemble-averaged transvalvular pressure waveforms from in vitro tests using a left heart simulator.
• High-resolution optical measurements to capture in vitro leaflet and stent kinematics.
• Definition and application of six new quantitative deformation metrics, including leaflet edge distances and stent post-to-stent post (SPTSP) distances.

Main Results:

• The FE structural model accurately predicted kinematic deformation metrics, with maximum errors around 10%.
• Predictions were particularly accurate during systole, where displacements are largest.
• The study successfully compared predicted kinematics with in vitro measurements, validating the model's efficacy.

Conclusions:

• The combined computational and experimental approach provides an effective method for studying PAV structural behavior.
• The newly introduced deformation metrics offer a robust way to quantify PAV kinematics.
• This research paves the way for improving the structural design and performance of prosthetic valves.