In silico modelling of aortic valve implants – predicting in vitro performance using finite element analysis

Abstract

The competing structural and hemodynamic considerations in valve design generally require a large amount of in vitro hydrodynamic and durability testing during development, often resulting in inefficient “trial-and-error” prototyping. While in silico modelling through finite element analysis (FEA) has been widely used to inform valve design by optimising structural performance, few studies have exploited the potential insight FEA could provide into critical hemodynamic performance characteristics of the valve. The objective of this study is to demonstrate the potential of FEA to predict the hydrodynamic performance of tri-leaflet aortic valve implants obtained during development through in vitro testing. Several variations of tri-leaflet aortic valves were designed and manufactured using a synthetic polymer and hydrodynamic testing carried out using a pulsatile flow rig according to ISO 5840, with bulk hydrodynamic parameters measured. In silico models were developed in tandem and suitable surrogate measures were investigated as predictors of the hydrodynamic parameters. Through regression analysis, the in silico parameters of leaflet coaptation area, geometric orifice area and opening pressure were found to be suitable indicators of experimental in vitro hydrodynamic parameters: regurgitant fraction, effective orifice area and transvalvular pressure drop performance, respectively.

Keywords:

• Heart valve design
• finite element analysis
• in vitro testing
• hydrodynamic performance

Acknowledgement

The authors wish to gratefully acknowledge William Hickey for his help with sample preparation and in vitro hydrodynamic testing.

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

Funding support was provided by the National University of Ireland Galway (NUIG) Hardiman scholarship while funding for the Vivitro Pulse Duplicator was provided by Enterprise Ireland CF20150340. This project is co-funded by the European Regional Development Fund (ERDF) under Ireland’s European Structural and Investment Funds Programme 2014-2020.