Experimental off-pump transventricular pulmonary valve replacement using a self-expandable valved stent: A new approach for pulmonary incompetence after repaired tetralogy of Fallot?
OBJECTIVE
Off-pump valve replacement using self-expandable stents is an emerging technique for pulmonary valve disease. However, significant limitations are the lack of easily available valve substitute to be inserted within the stent and, in the setting of repaired tetralogy of Fallot, the existence of huge pulmonary trunk. We report the first experimental results of a transventricular approach using a decellularized porcine xenograft mounted in a self-expandable stent.


METHODS
Pulmonary valve replacement was realized in 15 lambs by direct access of the infundibulum through a left thoracotomy, combined with pulmonary artery banding. Animals were followed by transthoracic echocardiography and, after control hemodynamic study, were electively killed either at day 7, month 1, or month 4 after implantation.


RESULTS
Implantation succeeded in all lambs. Two animals died after implantation (1 pneumothorax and 1 endocarditis). Doppler echocardiographic follow-up did not show any significant transvalvular gradient and showed only mild pulmonary regurgitation. The hemodynamic control before termination revealed a systolic pulmonary valve gradient of 18.5 +/- 12.4 mm Hg at 1 week (n = 4), 13.5 +/- 10.6 mm Hg at 1 month (n = 4), and 4.3 +/- 4.9 mm Hg at 4 months (n = 5). Gross examination demonstrated the presence of connective tissue between the valved stent and pulmonary wall, which increased with time.


CONCLUSIONS
Fifteen lambs underwent successful deployment of a self-expandable valved stent in the pulmonary position using a transventricular approach. This technique combined with pulmonary artery banding could be a therapeutic option for pulmonary insufficiency after repair of tetralogy of Fallot with a transannular patch.
Godart
François
F
Pôle de Cardiologie et Maladies Vasculaires, Centre Hospitalier Régional et Universitaire de Lille, Service des Maladies Cardiovasculaires Infantiles et Congénitales, Lille cedex, France. f-godart@chru-lille.fr
Bouzguenda
Ivan
I
Juthier
Francis
F
Wautot
Fabrice
F
Prat
Alain
A
Rey
Christian
C
Corseaux
Delphine
D
Ung
Alexandre
A
Jude
Brigitte
B
Vincentelli
André
A
D000818:Animals; D002315:Cardiopulmonary Bypass; D004195:Disease Models, Animal; D004452:Echocardiography / Q000379:methods; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D018583:Pliability; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011664:Pulmonary Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012756:Sheep; D015607:Stents; D015996:Survival Rate; D013771:Tetralogy of Fallot / Q000150:complications / Q000601:surgery; D016896:Treatment Outcome