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Author Notes:

Address for correspondence: Wei Sun, Ph.D., The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30313-2412, Phone: (404) 385-1245, wei.sun@bme.gatech.edu

CONFLICTS OF INTEREST: None.

Subject:

Research Funding:

This research was supported in part by the NIH grants HL104080 and HL108240.

Keywords:

  • Heart valve biomechanics
  • Optimization analysis
  • Finite element analysis
  • Transcatheter aortic valve implantation
  • Aortic stenosis

Simulated Transcatheter Aortic Valve Deformation: A Parametric Study on the Impact of Leaflet Geometry on Valve Peak Stress

Tools:

Journal Title:

International Journal for Numerical Methods in Biomedical Engineering

Volume:

Volume 33, Number 3

Publisher:

, Pages e02814-e02814

Type of Work:

Article | Post-print: After Peer Review

Abstract:

In this study, we developed a computational framework to investigate the impact of leaflet geometry of a transcatheter aortic valve (TAV) on the leaflet stress distribution, aiming at optimizing TAV leaflet design to reduce its peak stress. Utilizing a generic TAV model developed previously [Li and Sun, Annals of Biomedical Engineering, 2010. 38(8): 2690-2701], we first parametrized the 2D leaflet geometry by mathematical equations, then by perturbing the parameters of the equations, we could automatically generate a new leaflet design, remesh the 2D leaflet model and generate a 3D leaflet model from the 2D design via a Python script. Approximately 500 different leaflet designs were investigated by simulating TAV closure under the nominal circular deployment and physiological loading conditions. From the simulation results, we identified a new leaflet design that could reduce the previously reported valve peak stress by about 5%. The parametric analysis also revealed that increasing the free edge width had the highest overall impact on decreasing the peak stress. A similar computational analysis was further performed for a TAV deployed in an abnormal, asymmetric elliptical configuration. We found that a minimal free edge height of 0.46 mm should be adopted to prevent central backflow leakage. This increase of the free edge height resulted in an increase of the leaflet peak stress. Furthermore, the parametric study revealed a complex response surface for the impact of the leaflet geometric parameters on the peak stress, underscoring the importance of performing a numerical optimization to obtain the optimal TAV leaflet design.

Copyright information:

© John Wiley & Sons Ltd

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