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DOI: 10.1055/s-0036-1571531
Preclinical Determination of the Best Functional Position for Transcatheter Heart Valves Implanted in Surgical Sutureless Bioprostheses
Objectives: Sutureless aortic valve prostheses have been increasingly used for the treatment of severe aortic valve stenosis. Currently, there is very little information available for the treatment of degenerated or dysfunctional sutureless prostheses. We sought to determine the best position of a transcatheter heart valve (THV) implanted as a valve-in-valve procedure (ViV) in an in-vitro model using small sutureless surgical bioprosthesis.
Methods: A 21mm Perceval®, Enable® or Intuity® sutureless aortic bioprosthesis was mounted into the aortic chamber of a pulse duplicator and a 23 mm balloon-expandable or a self-expandable THV was deployed (valve-in-valve) in two different positions. Under different hydrodynamic conditions, performance of the THV was characterized by mean transvalvular pressure gradient (TVPG), effective orifice area (EOA) and regurgitation volume. Furthermore, leaflet kinematics was assessed with high-speed video recordings and X-ray imaging was performed to create a ‘blueprint’ for a future patient procedure.
Results: For all THV-sutureless valve-combinations, the higher position of the THV performed better than the lower one and a reduction of the mean TVPG was observed. Simultaneously, an increase in EOA of the THV was seen in the higher position. Leaflet kinematics revealed impaired leaflet motion of the implanted THV in the lower position. In contrast, leakage volume was relatively small and similar independent of the THV position.
Conclusions: Supra-annular implantation of a THV in a small sutureless surgical bioprosthesis reduces mean TVPG, increases EOA and reduces risk of impaired leaflet function of the THV. Fluoroscopy images of the best functional ViV positions are presented as a blueprint for future patient procedures.