Investigation of Leaflet Geometry in a Percutaneous Aortic Valve With the Use of Fluid-Structure Interaction Simulation

Prosthetic aortic valves have been used for the replacement of dysfunctional native aortic valves in humans for more than fifty years. Current prosthetic valves have significant limitations and the development of improved aortic valve prostheses remains an important research focus area. This paper investigates one of the newer additions to the family of replacement valves, namely the stented percutaneous valve. An important design aspect of stented percutaneous valves, is the configuration of the leaflet's attachment to the surrounding stent. There are essentially two possible configurations: The first method is attaching the leaflets in a straight configuration, and the second method is to attach the leaflets in a curved configuration. Finite element models of both configurations were created, and the behavior of these configurations was then studied using a fluid-structure interaction (FSI) simulation. The FSI simulation was validated by means of comparing simulation results to actual measurements from a pulse duplicator using prototype valves of both configurations. The FSI results showed no significant difference between the valves' opening and closing behaviors. The von Mises stress distributions proved to be the largest differentiating and decisive factor between the two valves. The FSI simulations did however show that the leaflets that are attached in the straight configuration form folds that resembles that of the curved configuration as well as the native valve, but to a larger scale. The effect that these folds might have on valve tissue fatigue leaves room for future investigation.