Minimally invasive off-pump valve-in-a-valve implantation: the atrial transcatheter approach for re-operative mitral valve replacement.
OBJECTIVE
This study was designed to evaluate the feasibility and haemodynamic performance of transcatheter valve-in-a-valve (VinV) implantation for failed mitral xenografts using a minimally invasive, transatrial, off-pump approach.


RESULTS
Nine adult sheep (71.1 +/- 3.4 kg) underwent mitral valve replacement with a 25 mm bioprosthesis using standard conventional techniques. After weaning from cardiopulmonary bypass, a transcatheter 23 mm pericardial prosthesis mounted on a balloon-inflatable steel stent was deployed within the conventional xenograft. The VinV implantation (10.1 +/- 0.9 min) was performed off-pump using an antegrade transatrial approach under fluoroscopic guidance successfully in all nine sheep. Mean transvalvular gradient was 4.6 +/- 1.0 mmHg, and five of nine sheep had no paravalvular leak with two sheep each having mild and moderate one. All transcatheter prostheses were confirmed in good position on post-mortem analysis. In an in vitro model, the minimum force required to dislodge the valve was 22.5 +/- 3.0 N, which was well above the normal estimated forces generated by the left ventricle (LV). When this model was attached to a LV assist device, the VinV withstood pressure loops of 300 mmHg, without dislocation or embolization.


CONCLUSIONS
Transatrial, transcatheter mitral VinV implantation is feasible off pump. This is a truly minimally invasive concept to treat patients with failed xenografts using a right lateral minithoracotomy.
Kempfert
Jörg
J
Department of Cardiac Surgery, Heartcenter, University of Leipzig, Struempellstrasse 39, 04289 Leipzig, Germany.
Blumenstein
Johannes M
JM
Borger
Michael A
MA
Linke
Axel
A
Lehmann
Sven
S
Pritzwald-Stegmann
Patrick
P
Chu
Michael W A
MW
Schuler
Gerhard
G
Falk
Volkmar
V
Mohr
Friedrich Wilhelm
FW
Walther
Thomas
T
D000818:Animals; D001705:Bioprosthesis; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods*; D005240:Feasibility Studies; D006350:Heart Valve Prosthesis / Q000592:standards; D019918:Heart Valve Prosthesis Implantation / Q000379:methods* / Q000639:trends; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008943:Mitral Valve / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012756:Sheep; D013908:Thoracotomy / Q000379:methods; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology