title: Transapical mitral valved stent implantation: comparison between circular and D-shaped design.
abstract: OBJECTIVE
  In this study two designs of a self-expanding valved stent were compared after off-pump implantation into the mitral valve to identify the superior one.
  
  
  RESULTS
  Two designs of a mitral valved stent were tested. The first design is composed of a circular atrial element connected to a tube-shaped ventricular element. In the second design, the atrial element is D-shaped to achieve better anatomical alignment. Prior to in vivo testing, the area with the highest risk of PVL was identified in a hydrostatic in vitro set-up. Subsequently, eight pigs received stents (circular, n=5; D-shaped, n=3) via apical access in the beating heart. Positioning and haemodynamics were evaluated by TEE and invasive pressure measurement pre-implantation, after 1 hr, and at two and four weeks. In vitro testing showed less PVL in the anteromedial region in D-shaped design stents (p<0.001). All stents were successfully deployed in vivo and six animals maintained normal haemodynamics for two weeks or longer. Rotational reorientation of all stents with D-shaped elements was observed. Both groups indicated no clinically relevant gradients over the mitral valved stent.
  
  
  CONCLUSIONS
  This study demonstrates that the circular design was superior to the D-shaped model after rotational reorientation of the latter occurred.
authors.affiliation: Department of Cardiovascular Surgery, Christian-Albrechts-University of Kiel, School of Medicine, Kiel, Germany.
authors.forename: Saskia
authors.initials: S
authors.lastname: Pokorny
authors.forename: Huangdong
authors.initials: H
authors.lastname: Dai
authors.forename: Telse
authors.initials: T
authors.lastname: Bähr
authors.forename: Katharina
authors.initials: K
authors.lastname: Huenges
authors.forename: Martin
authors.initials: M
authors.lastname: Marczynski-Bühlow
authors.forename: Michael M
authors.initials: MM
authors.lastname: Morlock
authors.forename: Jochen
authors.initials: J
authors.lastname: Cremer
authors.forename: Georg
authors.initials: G
authors.lastname: Lutter
mesh_terms: D000818:Animals; D017548:Echocardiography, Transesophageal; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation*; D006439:Hemodynamics; D008422:Materials Testing; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D023421:Models, Animal; D011474:Prosthesis Design; D013552:Swine; D013997:Time Factors