title: Transcatheter heart valve crimping and the protecting effects of a polyester cuff.
abstract: BACKGROUND
  Prior to deployment, the percutaneous heart valves must be crimped and loaded into sheaths of diameters that can be as low as 6mm for a 23mm diameter valve. However, as the valve leaflets are fragile, any damage caused during this crimping process may contribute to reducing its long-term durability in vivo.
  
  
  METHODS
  Bovine pericardium percutaneous valves were manufactured as follows. The leaflets were sutured on a nitinol frame. A polyester cuff fabric served as a buffer between the pericardium and the stent. Two valves were crimped and one valve was used as control. The valves were examined in gross observation and micro-CT scan and then the leaflets were processed for histology and analyzed in scanning electron microscopy, light microscopy and transmission electron microscopy.
  
  
  RESULTS
  Crimping of the valves resulted in the increase thickness of the leaflets and there was no evidence of additional delamination. The heavy prints of the stents were irregularly distributed on the outflow surface in the crimped devices and were shallow and did not penetrate throughout the thickness of the leaflets. However, the wavy microscopy of collagen fiber bundles was well preserved. They were found to remain individualized without any agglutination as shown by the regular banding appearance.
  
  
  CONCLUSIONS
  Crimping of self-deployable valves per se caused only minor damages to the leaflets. However, the procedure could be refined in order to minimize areas of high pressure and swelling of the tissue that can be accompanied with flow surface disruption and increase of the hydraulic conductance. The incorporation of a polyester buffer serves to prevent the deleterious effects that may be caused if the pericardium tissue were in direct contact with the nitinol stent.
authors.affiliation: Department of surgery, faculty of medicine, Laval university and axe médecine régénérative, centre de recherche, CHU, Vandry building, 2325, rue de l'Université, GIV OA6 Québec, Canada. Electronic address: robert.guidoin@fmed.ulaval.com.
authors.forename: R
authors.initials: R
authors.lastname: Guidoin
authors.affiliation: Services de chirurgie cardiovasculaire et de pathologie, hôpital européen Georges-Pompidou, 75015 Paris, France.
authors.forename: R
authors.initials: R
authors.lastname: Zegdi
authors.affiliation: Key laboratory of textile science and technology of Ministry of Education and College of Textile, Donghua university, Shanghai, China.
authors.forename: J
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of surgery, faculty of medicine, Laval university and axe médecine régénérative, centre de recherche, CHU, Vandry building, 2325, rue de l'Université, GIV OA6 Québec, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Mao
authors.affiliation: Department of surgery, faculty of medicine, Laval university and axe médecine régénérative, centre de recherche, CHU, Vandry building, 2325, rue de l'Université, GIV OA6 Québec, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Rochette-Drouin
authors.affiliation: Peninsula school of medicine and dentistry, Plymouth, Devon, United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: How
authors.affiliation: Key laboratory of textile science and technology of Ministry of Education and College of Textile, Donghua university, Shanghai, China.
authors.forename: X
authors.initials: X
authors.lastname: Guan
authors.affiliation: Services de chirurgie cardiovasculaire et de pathologie, hôpital européen Georges-Pompidou, 75015 Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Bruneval
authors.affiliation: Key laboratory of textile science and technology of Ministry of Education and College of Textile, Donghua university, Shanghai, China.
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of surgery, faculty of medicine, Laval university and axe médecine régénérative, centre de recherche, CHU, Vandry building, 2325, rue de l'Université, GIV OA6 Québec, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Germain
authors.affiliation: Department of surgery, faculty of medicine, Laval university and axe médecine régénérative, centre de recherche, CHU, Vandry building, 2325, rue de l'Université, GIV OA6 Québec, Canada.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000497:Alloys / Q000009:adverse effects; D000818:Animals; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D002417:Cattle; D006350:Heart Valve Prosthesis; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D010496:Pericardium; D011091:Polyesters; D015607:Stents / Q000009:adverse effects; D065467:Transcatheter Aortic Valve Replacement / Q000295:instrumentation*
chemical_list: D000497:Alloys; D011091:Polyesters; C013616:nitinol
keywords: Bovine pericardium; Collerette de suture; Crimping; Fabric skirt; Péricarde de veau; Sertissage; Transcatheter valves; Valves percutanées