title: Percutaneous valve replacement: significance of different delivery systems in vitro and in vivo.
abstract: OBJECTIVE
  Percutaneous heart valve replacement is an exciting growing field in cardiovascular medicine yet still with some major problems. Only sophisticated improvement of the instruments could make it a real alternative to conventional surgery. Therefore, the aim of this study was to evaluate different delivery devices for percutaneous heart valve replacement in vitro and in vivo.
  
  
  METHODS
  A catheter prototype designed by our group, and two commercially available devices for the delivery of esophageal stents and aortic endoprostheses, were tested. After in vitro experiments, an ovine animal model of transfemoral pulmonary valve implantation was established using biological valved self-expanding stents. Only the delivery device for aortic endografts (Medtronic, Talent, Santa Rosa, CA, USA) allowed fast in vitro procedures without material fatigue. This device was chosen for the in vivo tests.
  
  
  RESULTS
  Technical success was achieved in 9 of 10 animals (90%). One animal died after perforation of the ventricular wall. Orthotopic pulmonary placement was performed in 6 animals and intentional supravalvular valved stent placement in 3 animals.
  
  
  CONCLUSIONS
  An adequate in vitro model for this evolving field of interventional heart valve replacement is presented. Furthermore, the present study pinpoints the key characteristics that are mandatory for a delivery system in percutaneous pulmonary valve implantation. With regard to the delivery device's ductility observed during this "venous" study, an approach to transfemoral aortic valve implantation seems feasible.
authors.affiliation: Department of Cardiovascular Surgery, School of Medicine, Christian Albrechts University of Kiel, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Attmann
authors.forename: Georg
authors.initials: G
authors.lastname: Lutter
authors.forename: René
authors.initials: R
authors.lastname: Quaden
authors.forename: Thomas
authors.initials: T
authors.lastname: Jahnke
authors.forename: Kristin
authors.initials: K
authors.lastname: Rumberg
authors.forename: Jochen
authors.initials: J
authors.lastname: Cremer
authors.forename: Stefan
authors.initials: S
authors.lastname: Muller-Hulsbeck
mesh_terms: D000792:Angiography; D000818:Animals; D005471:Fluoroscopy; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D066298:In Vitro Techniques; D011474:Prosthesis Design; D012756:Sheep; D015607:Stents; D014057:Tomography, X-Ray Computed