title: Percutaneous transcatheter one-step mechanical aortic disc valve prosthesis implantation: a preliminary feasibility study in swine.
abstract: OBJECTIVE
  To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves.
  
  
  METHODS
  The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation.
  
  
  RESULTS
  MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle.
  
  
  CONCLUSIONS
  The tested MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP.
authors.affiliation: Intensive Care Unit, Clinic of Cardiology, Institute for Clinical and Experimental Medicine, Vídenská 1958/9, 140 21 Prague 4, Czech Republic. jan.sochman@medicon.cz
authors.forename: Jan
authors.initials: J
authors.lastname: Sochman
authors.forename: Jan H
authors.initials: JH
authors.lastname: Peregrin
authors.forename: Miloslav
authors.initials: M
authors.lastname: Rocek
authors.forename: Hans A
authors.initials: HA
authors.lastname: Timmermans
authors.forename: Dusan
authors.initials: D
authors.lastname: Pavcnik
authors.forename: Josef
authors.initials: J
authors.lastname: Rösch
mesh_terms: D000818:Animals; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging / Q000601:surgery*; D004195:Disease Models, Animal; D005240:Feasibility Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D011474:Prosthesis Design; D011859:Radiography; D015607:Stents; D013552:Swine