Evaluation of an aortic valve prosthesis: Fluid-structure interaction or structural simulation?

Giulia Luraghi,Wei Wu,Francesco De Gaetano,Josè Felix Rodriguez Matas,Geoff D Moggridge,Marta Serrani,Joanna Stasiak,Maria Laura Costantino,Francesco Migliavacca

doi:10.1016/j.jbiomech.2017.04.004

Giulia Luraghi, Wei Wu + Show 7 more

Open Access

https://doi.org/10.1016/j.jbiomech.2017.04.004

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Abstract

Bio-inspired polymeric heart valves (PHVs) are excellent candidates to mimic the structural and the fluid dynamic features of the native valve. PHVs can be implanted as prosthetic alternative to currently clinically used mechanical and biological valves or as potential candidate for a minimally invasive treatment, like the transcatheter aortic valve implantation. Nevertheless, PHVs are not currently used for clinical applications due to their lack of reliability. In order to investigate the main features of this new class of prostheses, pulsatile tests in an in-house pulse duplicator were carried out and reproduced in silico with both structural Finite-Element (FE) and Fluid-Structure interaction (FSI) analyses. Valve kinematics and geometric orifice area (GOA) were evaluated to compare the in vitro and the in silico tests. Numerical results showed better similarity with experiments for the FSI than for the FE simulations. The maximum difference between experimental and FSI GOA at maximum opening time was only 5%, as compared to the 46.5% between experimental and structural FE GOA. The stress distribution on the valve leaflets clearly reflected the difference in valve kinematics. Higher stress values were found in the FSI simulations with respect to those obtained in the FE simulation. This study demonstrates that FSI simulations are more appropriate than FE simulations to describe the actual behaviour of PHVs as they can replicate the valve-fluid interaction while providing realistic fluid dynamic results.

Highlights

In the arena of heart valve prostheses, bio-inspired polymeric heart valves (PHVs) are excellent candidates to mimic the shape, and the structural and fluid dynamic behaviour of the native valve (Kuan et al, 2011)
For test A, only the fluidstructure interaction (FSI) simulation reproduced the asymmetric opening observed in the experiment, with the thicker leaflet remaining closed (Fig. 5 Test A - FSI)
The present study demonstrates that FSI simulations are more appropriate than finite element (FE) analyses to describe the real behaviour of a PHVs

Summary

Introduction

In the arena of heart valve prostheses, bio-inspired polymeric heart valves (PHVs) are excellent candidates to mimic the shape, and the structural and fluid dynamic behaviour of the native valve (Kuan et al, 2011). They aim at combining the main advantages from the mechanical and biological valve prostheses. TAVR, which is a proven technology nowadays, consists in the insertion of a stented valve in the aortic root using a catheter (Cribier et al, 2002) In both applications of PHVs, used as a traditional valve prosthesis or as a TAVR, a number of critical aspects influencing prosthesis performance are still present; they

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