Reducing the Risk of Leaflet Thrombosis following Transcatheter Aortic Valve-in-Valve Implantation by BASILICA Procedure: A Computational Simulation Study

Objective: Leaflet thrombosis following transcatheter aortic valve-in-valve (ViV) is an increasingly recognized complication. We have previously shown that the geometric confinement of transcatheter aortic valves (TAVs), introduced by the leaflet and frame of degenerated bioprosthesis, disturbs the natural flow field on the TAV leaflets. The confinement increases blood stasis on the TAV leaflets and consequently increases the likelihood of thrombogenesis. The goal of this study was to assess the effect of transcatheter laceration of the degenerated bioprosthetic valve leaflets, also known as BASILICA, on the likelihood of leaflet thrombosis using computational simulations. Methods: Idealized computational models representing a 26-mm SAPIEN 3 implanted in 29-mm Mitroflow surgical bioprosthesis were developed before (Figure-1a) and after (Figure-1b) the BASILICA procedure. Flow fields were obtained via fluid-solid interaction simulations. Regions of high blood residence time (BRT > 0.5s), which are highly prone to platelet activation, were compared between the models. Results: Summary histogram of reduction of BRT on the surface of left-coronary and right-coronary leaflets is shown in Figure-1c. On the left-coronary leaflet, the areas with high BRT reduced considerably from 50.5% in the ViV model without leaflet laceration to 37.3% in the ViV model with leaflet laceration. On the right-coronary leaflet, the areas with high BRT reduced from 72.2% in the ViV model without leaflet laceration to 67.9% in the ViV model with leaflet laceration. No reduction in areas of high BRT was observed in the non-coronary leaflet. Conclusions: Transcatheter laceration was invented to prevent coronary obstruction in ViV procedures. The procedure has the potential to reduce the areas with high BRT on the aortic surface of left- and right-coronary leaflets and consequently reduce the risk of leaflet thrombosis.