Assessing the Risk of Leaflet Thrombosis following Transcatheter Aortic Valve-in-Valve Procedures: A Simulation Study *

Transcatheter aortic valve-in-valve (ViV) implantation is a safe and effective treatment for patients with failed surgical or transcatheter bioprostheses. Recently concerns have been raised about the occurrence of subclinical leaflet thrombosis following the ViV procedures. The aim of this study was to assess the likelihood of leaflet thrombosis post-ViV after the use of transcatheter aortic valves with intra-annular and supra-annular design. In the study, we developed a fluid-solid interaction modeling approach to quantify blood stasis on the leaflets of 26-mm Edwards SAPIEN 3 and 26-mm Medtronic CoreValve. Three-dimensional flow fields of the two valves were obtained using computational simulations. The simulation results were also validated by experimental testing (particle imaging velocimetry) in a pulse duplicator system. The results showed a significantly longer blood stasis on the leaflets of the SAPIEN 3 compared to the CoreValve. A good agreement was also observed between the simulation results and the experimental data. The study suggests that the use of transcatheter aortic valves with supra-annular design reduces blood stasis on the leaflets and consequently has the potential to reduce the likelihood of leaflet thrombosis following the ViV procedures.