title: Preclinical determination of the best functional position for transcatheter heart valves implanted in rapid deployment bioprostheses.
abstract: OBJECTIVE
  The aim of this study was to determine the best functional position of a transcatheter heart valve (THV) implanted as a valve-in-valve (ViV) procedure in small rapid deployment valves (RDV) in an in vitro model.
  
  
  RESULTS
  A 21 mm Perceval, Enable or INTUITY RDV was mounted into a pulse duplicator and a 23 mm balloon-expandable or a self-expanding THV was deployed (valve-in-valve) in two different positions. Under physiological hydrodynamic conditions, the performance of the THV was characterised by mean transvalvular pressure gradient (MPG), effective orifice area (EOA) and regurgitation volume (RV). Leaflet kinematics were assessed with high-speed video recordings, and X-ray images were acquired. All THV/RDV combinations met ISO requirements regarding hydrodynamic performance. In most cases, the higher position of the THV performed better than the lower one in terms of a lower MPG and increased EOA. Leaflet motion of the implanted THV was impaired in the lower position. In contrast, regurgitation volumes were relatively small and similar, regardless of the THV position.
  
  
  CONCLUSIONS
  ViV implantation of a THV in a small RDV yielded satisfactory hydrodynamic results. In most cases, a high implantation position achieved lower MPG, higher EOA and a reduced risk of impaired THV leaflet function. Fluoroscopy images of the best functional ViV positions are presented as a blueprint for patient procedures.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Ruhr-University Bochum, Bad Oeynhausen, Germany.
authors.forename: Timm
authors.initials: T
authors.lastname: Schäfer
authors.forename: Christian
authors.initials: C
authors.lastname: Doose
authors.forename: Buntaro
authors.initials: B
authors.lastname: Fujita
authors.forename: Marc
authors.initials: M
authors.lastname: Utzenrath
authors.forename: Sandrine
authors.initials: S
authors.lastname: Egron
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmitz
authors.forename: Smita
authors.initials: S
authors.lastname: Scholtz
authors.forename: Maximilian
authors.initials: M
authors.lastname: Kütting
authors.forename: Kavous
authors.initials: K
authors.lastname: Hakim-Meibodi
authors.forename: Jochen
authors.initials: J
authors.lastname: Börgermann
authors.forename: Jan
authors.initials: J
authors.lastname: Gummert
authors.forename: Ulrich
authors.initials: U
authors.lastname: Steinseifer
authors.forename: Stephan
authors.initials: S
authors.lastname: Ensminger
mesh_terms: D001022:Aortic Valve Insufficiency / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000601:surgery*; D001705:Bioprosthesis; D006328:Cardiac Catheterization / Q000295:instrumentation / Q000379:methods; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation / Q000379:methods; D006801:Humans