Transapical approach for sutureless stent-fixed aortic valve implantation: experimental results.
OBJECTIVE
Percutaneous aortic valve implantation has been performed in patients with severe aortic stenosis judged as nonsurgical candidates. We evaluated a facilitated transapical antegrade approach for potential use in surgical high-risk patients.


METHODS
A pericardial xenograft fixed within a 23-mm stent (Cribier-Edwards aortic prosthesis, Edwards Inc., Irvine, CA, USA) was implanted using a transapical approach in fifteen 35-45 kg pigs. A limited or a full sternotomy was used to transapically introduce a crimped valve through a 24-F sheath. Deployments were performed on the beating heart either with ventricular unloading using femoro-femoral cardiopulmonary bypass (CPB) or rapid ventricular pacing (RVP), all under fluoroscopic and echocardiographic visualization.


RESULTS
All valves were successfully deployed at the target site with acceptable visualization of the noncalcified annulus. Valve migration occurred in six procedures (three distal and three retrograde) secondary to inadequate reduction of ventricular output, unfavorable annular anatomy, excessive crimping of the valve, and dislodgement by the delivery balloon. Exact positioning of the valve into the target area was confirmed by autopsy at the end of the procedures. Paravalvular leak was noted in five implants.


CONCLUSIONS
The transapical approach provides a safe, accurate, and effective route for facilitated antegrade delivery of a stent-fixed valve. Advanced stent design will lead to better stability of the implant and may minimize the risk of paravalvular leakage in future. Identifying the appropriate population for human feasibility trials remains a challenge.
Walther
Thomas
T
Universität Leipzig, Herzzentrum, Klinik für Herzchirurgie, Strümpellstrasse 39, 04289 Leipzig, Germany. walt@medizin.uni-leipzid.de
Dewey
Todd
T
Wimmer-Greinecker
Gerhard
G
Doss
Mirko
M
Hambrecht
Rainer
R
Schuler
Gerhard
G
Mohr
Friedrich W
FW
Mack
Michael
M
D000818:Animals; D001021:Aortic Valve / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000601:surgery*; D004195:Disease Models, Animal; D005471:Fluoroscopy; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D011474:Prosthesis Design; D015607:Stents; D013552:Swine; D014183:Transplantation, Heterologous