title: Transapical implantation of a novel self-expanding sutureless aortic valve prosthesis.
abstract: OBJECTIVE
  To date, transapical aortic valve implantation has required a balloon-expandable stented valve prosthesis. More recently, a novel self-expanding sutureless stented bovine pericardial prosthesis has been developed which allows rapid aortic valve replacement via an open transaortic approach in humans. The aim of this animal study was to develop a reliable protocol to facilitate the transapical implantation of this self-expanding valve in a porcine model.
  
  
  METHODS
  Off-pump transapical aortic valve implantation was performed through a left mini-thoracotomy using a bovine pericardial valve mounted on a self-expandable nitinol stent of size 21 mm and 23 mm in 11 pigs (average weight 60 kg). The crimped valve was introduced through the left ventricular apex using a flexible and steerable delivery sheath, using a three-step technique. Biplane fluoroscopy and transesophageal echocardiography were simultaneously used for guidance. Successful adjustment of alignment along three axes prior to deployment of the valve was accomplished in each animal. Deployments were performed during a period of rapid pacing.
  
  
  RESULTS
  All valves were successfully deployed and functioned normally following transapical removal of the delivery system. Paravalvular leak was documented in one case (9.1%) due to prosthetic misalignment. There was no evidence of valve migration. Correct anatomic seating was confirmed during post-procedure necropsy.
  
  
  CONCLUSIONS
  Successful transapical implantation of a novel self-expandable bovine pericardial valve was accomplished in 11 animals, without cardiopulmonary bypass. A flexible, steerable delivery system with a three-step release mechanism allowed precise positioning of the valve with a low rate of paravalvular leakage, and excellent device stability.
authors.affiliation: Department of Cardiovascular Surgery, University Hospital, Berne, Switzerland. mario.stalder@insel.ch
authors.forename: Mario
authors.initials: M
authors.lastname: Stalder
authors.forename: Rakesh M
authors.initials: RM
authors.lastname: Suri
authors.forename: Eva S
authors.initials: ES
authors.lastname: Kraehenbuehl
authors.forename: Gerrit
authors.initials: G
authors.lastname: Hellige
authors.forename: Peter
authors.initials: P
authors.lastname: Wenaweser
authors.forename: Claudia
authors.initials: C
authors.lastname: Zobrist
authors.forename: Harzell V
authors.initials: HV
authors.lastname: Schaff
authors.forename: Thierry P
authors.initials: TP
authors.lastname: Carrel
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D002404:Catheterization; D047549:Coronary Artery Bypass, Off-Pump; D005471:Fluoroscopy; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D019060:Minimally Invasive Surgical Procedures; D011183:Postoperative Complications; D015641:Radiography, Interventional; D034421:Sus scrofa; D013908:Thoracotomy