title: A new self-expandable aortic valved stent deployed above native leaflets for aortic insufficiency: an in vitro study.
abstract: OBJECTIVE
  The aim of this paper was to develop a new self-expandable aortic valved stent following the shape of the sinus of Valsalva, which can be deployed above native leaflets for aortic regurgitation, and study it's effect on coronary artery flow when orthotopic implantation in and above native leaflets.
  
  
  METHODS
  New self-expandable aortic valved stent consist of nitinol stent and bovine pericardium, and was designed following the shape of the sinus of Valsalva, the bovine pericardium was tailed as native leaflet. Thirty-six swine hearts were divided into three equal groups of twelve. In Group A (N.=12), the new self-expandable aortic valved stents deployed in native leaflets. In Group B (N.=12), the new self-expandable aortic valved stents deployed above native leaflets. In Group C (N.=12), the cylinder-like valved stents deployed only in native leaflets. The measurements of each coronary flow rate and endoscopic inspections were repeated post-implantation.
  
  
  RESULTS
  In Group A and C, valve implantation in native leaflets resulted in a significant decrease in both left and right coronary flows. In Group B, no significant change in either right or left coronary flow was found after new self-expandable aortic valved stent placement. Endoscopic inspections showed that in group A and C the native leaflets sandwiched between valved stent and aortic wall, whereas, in group B the native leaflets were under the artificial leaflets.
  
  
  CONCLUSIONS
  Two kinds of stents deployed in native leaflets affect left and right coronary flows significantly. No significant effect was found when the new self-expandable aortic valved stent deployed above native leaflets. This new self-expandable aortic valved stent can be deployed above the native leaflets, which avoids the obstruction of native leaflets on coronary flow.
authors.affiliation: Department of Thoracic-Cardiovascular Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: H
authors.initials: H
authors.lastname: Huang
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.forename: J
authors.initials: J
authors.lastname: Shao
authors.forename: J
authors.initials: J
authors.lastname: Cai
authors.forename: Y
authors.initials: Y
authors.lastname: Mei
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D001021:Aortic Valve; D001022:Aortic Valve Insufficiency / Q000601:surgery*; D001705:Bioprosthesis; D003326:Coronary Circulation / Q000502:physiology; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D066298:In Vitro Techniques; D011474:Prosthesis Design; D015607:Stents; D013552:Swine