title: Beating-heart implantation of adjustable length mitral valve chordae: acute and chronic experience in an animal model.
abstract: OBJECTIVE
  This study aimed to determine the acute and chronic performance of a new system designed to conduct beating-heart implantation and off-pump adjustment of neochordal length.
  
  
  METHODS
  In 14 adult sheep (group A) selected to undergo beating-heart cardiopulmonary bypass, the left atrium was opened through a left thoracotomy. Two or more primary chordae in the A2 region were severed to produce a model of a flail leaflet. A chordal adjustment mechanism (V-Chordal, Valtech Cardio Ltd., Or-Yehuda, Israel) was affixed to the head of the papillary muscle. The system includes two adjustable neochordae. The distal end of the neochordae was sutured to the flail segment without estimating the appropriate length. The neochordal length was adjusted off-pump under real-time echo-guidance. The adjustment tool was removed and the atriotomy was closed with a purse-string suture. Control animals (group B, n=4) were implanted with the conventional neochordae. Animals in both groups were sacrificed 3 months after the procedure.
  
  
  RESULTS
  In both groups, prior to repair, mitral regurgitation (MR) was severe in all animals. In group A, following adjustment of neochordae, MR was absent in all animals, with the exception of two animals that had residual 2+ MR irresponsive to neochordae adjustments. In group B, MR was 2+ in two of the four animals following repair. At 3 months, mitral competence was stable in all animals. At necropsy, normal healing of the papillary head and leaflet was observed in both the groups.
  
  
  CONCLUSIONS
  The V-Chordal system simplifies the process of neochordal implantation and precise off-pump adjustment of the neochordal length to correct MR occurring due to a flail leaflet. This technology may improve the technical feasibility for adoption of chordal repair during open or minimally invasive surgical procedures.
authors: Cardiothoracic Surgery, San Raffaele Hospital, Milano, Italy. francesco.maisano@hsr.it
authors: Francesco
authors: F
authors: Maisano
authors: Micaela
authors: M
authors: Cioni
authors: Joerg
authors: J
authors: Seeburger
authors: Volkmar
authors: V
authors: Falk
authors: Friedrich Wilhelm
authors: FW
authors: Mohr
authors: Michael J
authors: MJ
authors: Mack
authors: Ottavio
authors: O
authors: Alfieri
authors: Hugo
authors: H
authors: Vanermen
mesh_terms: D000818:Animals; D002315:Cardiopulmonary Bypass / Q000379:methods; D002815:Chordae Tendineae / Q000000981:diagnostic imaging / Q000601:surgery*; D004195:Disease Models, Animal; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000601:surgery*; D010210:Papillary Muscles / Q000601:surgery; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000379:methods; D012756:Sheep; D013536:Suture Techniques; D018084:Ultrasonography, Interventional