Fatigue modeling in percutaneous caval valved stents

摘要

Heterotopic implantation of transcatheter tricuspid valve is a new treatment option for tricuspid regurgitation. Transcatheter tricuspid valves (inferior and superior) are implanted at the cavo-atrial junctions (CAJ) in order to avoid the challenging task of anchoring the valve in the complex tricuspid valve annulus. However, little is known about the complex loading that the valve stent can withstand at the cavo-atrial junction, which is critical for fatigue life prediction and device development. In this study, we developed a finite element based fatigue model taking into account the major fatigue loads that may be acting upon the two caval stents, after deployment. The simulation results showed that both stent designs had a fatigue safety factor (FSF) greater than 1 under these complex loading conditions. It was also observed from our simulation that leaflets loads contributed more towards the fatigue of valved stents compared to the other loads. The fatigue model presented in this study provides a simple, fast and cost-effective tool to quantitatively determine the fatigue resistance of caval valved stents subjected to cyclic loads. The simulated bench testing proposed here can be of great value to the design and development of new prosthetic cava stented valves.