title: Novel self-expandable, stent-based transcatheter pulmonic valve: a preclinical animal study.
abstract: BACKGROUND
  Because transcatheter implantation of pulmonary valve is indicated for limited-size dysfunctional right ventricular outflow tract only as a balloon-expandable stent, we investigated the feasibility of a large-diameter self-expandable valved stent and the durability of the valve after >6 months.
  
  
  METHODS
  We made a nitinol-wire-based, self-expandable valved stent with leaflets made from porcine pericardium. The porcine pericardium was treated with α-galactosidase, glutaraldehyde, and glycine after decellularization. After cutting the inguinal or cervical area, we implanted a valved stent in 12 sheep through the femoral or jugular vein by using an 18-Fr delivery catheter, controlling the catheter handles and hook block under fluoroscopic and echocardiographic guidance.
  
  
  RESULTS
  The mean body weight of sheep was 43.9 kg. We successfully implanted valved stents (diameter: 24 mm in 7 sheep, 26 mm in 5 sheep) in good position in 8 sheep, in the main pulmonary artery (PA) in 2 sheep, and in the right ventricular outlet tract (RVOT) in 2 sheep. We sacrificed 8 sheep (6 sheep in good position, 1 sheep in the main PA, and 1 sheep in the RVOT) after >6 months. Five of the 6 sheep implanted in good position showed well-preserved valve morphology at the time of sacrifice. Histologic findings after routine sacrifice showed well-maintained collagen wave structure and no visible calcification in all explanted valve leaflets.
  
  
  CONCLUSIONS
  Transcatheter implantation of a nitinol-wire-based, self-expandable valved stent in the pulmonic valve was feasible, and stents implanted in good position showed well-preserved valve leaflets with functional competence in the mid-term results.
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Republic of Korea; Xenotransplantation Research Center, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Gi Beom
authors.initials: GB
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Children's Hospital, Seoul, Republic of Korea; Xenotransplantation Research Center, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Hong-Gook
authors.initials: HG
authors.lastname: Lim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Children's Hospital, Seoul, Republic of Korea; Xenotransplantation Research Center, Seoul National University Hospital, Seoul, Republic of Korea. Electronic address: kyj@plaza.snu.ac.kr.
authors.forename: Yong Jin
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Seoul National University Bundang Hospital, Gyeonggi-do, Republic of Korea; Xenotransplantation Research Center, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Choi
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Republic of Korea; Xenotransplantation Research Center, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Bo Sang
authors.initials: BS
authors.lastname: Kwon
authors.affiliation: Xenotransplantation Research Center, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Saeromi
authors.initials: S
authors.lastname: Jeong
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D006328:Cardiac Catheterization / Q000295:instrumentation / Q000379:methods*; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation / Q000379:methods*; D011474:Prosthesis Design / Q000295:instrumentation / Q000379:methods; D011664:Pulmonary Valve / Q000601:surgery*; D012756:Sheep; D015607:Stents; D013552:Swine
keywords: Catheters; Nitinol; Pulmonary valve; Stents; α-Galactosidase