title: Medtentia double helix mitral annuloplasty system evaluated in a porcine experimental model.
abstract: OBJECTIVE
  : To further develop and improve minimally invasive surgical procedures, dedicated appropriate surgical devices are mandatory. In this study, the safety and feasibility of implanting the novel Medtentia double helix mitral annuloplasty ring, which uses the key-ring principle to potentially allow faster and sutureless implantation, was assessed using both minimally invasive and conventional surgical techniques. Because of ethical concerns, a human compatible porcine experimental model of mitral valve surgery was used.
  
  
  METHODS
  : Twelve 50-kg pigs were allocated to implantation of the Medtentia double helix annuloplasty ring using conventional midline sternotomy including cardioplegic arrest or a minimally invasive approach using peripheral cannulation and left ventricular fibrillation. Ten weeks after surgery, echocardiography was performed to assess mitral valve function. Animals were then killed, and gross mitral valve anatomy was examined ex vivo.
  
  
  RESULTS
  : All animals survived 10 weeks without developing mitral regurgitation, structural leaflet damage, ring dehiscence, or endocarditis. In the minimally invasive compared with the midline sternotomy group (mean ± SD), significantly reduced recovery time (80 ± 16 vs. 327 ± 23 minutes, P < 0.01) and a tendency toward increased operating time (199 ± 33 vs. 168 ± 15 minutes, P > 0.05) and cardiopulmonary bypass time (98 ± 12 vs. 91 ± 11 minutes, P > 0.05) were observed.
  
  
  CONCLUSIONS
  : By using a both minimally invasive and conventional midline sternotomy implantation techniques, the Medtentia double helix annuloplasty ring showed no mitral valve dysfunction or tissue damage 10 weeks postoperatively.
authors.affiliation: From the *Department of Cardiothoracic and Vascular Surgery T and Institute of Clinical Medicine, Aarhus University Hospital-Skejby, Aarhus, Denmark; and †Department of Cardiothoracic Surgery, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Henrik
authors.initials: H
authors.lastname: Jensen
authors.forename: Jarmo
authors.initials: J
authors.lastname: Simpanen
authors.forename: Morten
authors.initials: M
authors.lastname: Smerup
authors.forename: Marianne
authors.initials: M
authors.lastname: Bjerre
authors.forename: Morten
authors.initials: M
authors.lastname: Bramsen
authors.forename: Kalervo
authors.initials: K
authors.lastname: Werkkala
authors.forename: Tiina
authors.initials: T
authors.lastname: Vainikka
authors.forename: J Michael
authors.initials: JM
authors.lastname: Hasenkam
authors.forename: Per
authors.initials: P
authors.lastname: Wierup