title: Percutaneous pulmonary polyurethane valved stent implantation.
abstract: OBJECTIVE
  Transfemoral application of pulmonary heart valves has been studied for the past 10 years. Nevertheless, size restriction of percutaneous heart valved stents is still imminent.
  
  
  METHODS
  In this study we implanted percutaneously a novel, low-profile polyurethane valved stent. Percutaneous implantation in pulmonary position was evaluated in 7 sheep. The new valved stent fits into a 14F delivery device. The self-expanding nitinol stent was produced by using a dip-coating technique, and a modified commercially available endovascular stent graft system served as a delivery device. The valved stents were deployed directly over the native pulmonary valve under fluoroscopic control. Transthoracic echocardiography was performed after 4 weeks. At the time of explantation, the animals were reanalyzed and killed. Angiography was performed at implantation and at the end of the study. Explanted constructs were analyzed macroscopically and microscopically.
  
  
  RESULTS
  Angiography and echocardiography in all animals demonstrated orthotopic position of the stents at the time of implantation and after 4 weeks. During the deployment procedure, rhythm disturbances occurred in all animals. The peak-to-peak transvalvular gradient was 2.3 +/- 1.2 mm Hg initially and 4.1 +/- 2.4 mm Hg at follow-up. One-month follow-up confirmed competent neovalves without any paravalvular leakage. Gross morphology demonstrated good opening and closure characteristics. No calcification was seen macroscopically, and surrounding tissue was free of calcification.
  
  
  CONCLUSIONS
  In the present study we demonstrated successful merging of 2 novel technologies for percutaneous treatment of pulmonary valve diseases using polyurethane stent valve constructs.
authors.affiliation: Department of Cardiovascular Surgery, Christian Albrechts University of Kiel, School of Medicine, 24105 Kiel, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Metzner
authors.forename: Kenji
authors.initials: K
authors.lastname: Iino
authors.forename: Ulrich
authors.initials: U
authors.lastname: Steinseifer
authors.forename: Anselm
authors.initials: A
authors.lastname: Uebing
authors.forename: Wiebke
authors.initials: W
authors.lastname: de Buhr
authors.forename: Jochen
authors.initials: J
authors.lastname: Cremer
authors.forename: Georg
authors.initials: G
authors.lastname: Lutter
mesh_terms: D000818:Animals; D005263:Femoral Artery; D011140:Polyurethanes; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000379:methods*; D011664:Pulmonary Valve / Q000601:surgery*; D012756:Sheep; D015607:Stents
chemical_list: D011140:Polyurethanes