Percutaneous pulmonary valve replacement: 3-month evaluation of self-expanding valved stents.
OBJECTIVE
In a recent study our group established an acute animal model of percutaneous pulmonary valve replacement using self-expanding nitinol stents. The present study was performed to evaluate these valved stents over a 3-month period.


METHODS
Bovine jugular xenografts were sutured into nitinol stents. Transfemoral implantation in the pulmonary position using a modified commercially available application device (with a 22-French outer diameter) was evaluated in 9 sheep.


RESULTS
Two sheep died shortly after successful valved stent implantation due to internal venous hemorrhage. Another 1 sheep died 2.5 months after the procedure due to vegetations on the neovalve leading to subtotal stenosis. All other animals survived the 3-month study time (n = 6). An orthotopic pulmonary valved stent position was achieved in 4 animals and a supravalvular position in 1. During the deployment procedure, rhythm disturbances occurred in all animals, and mean arterial blood pressure dropped from 83.9 +/- 26.0 mm Hg to 68.3 +/- 22.3 mm Hg (p = 0.006) (n = 5). The peak-to-peak transvalvular gradient was 5.1 +/- 4.0 mm Hg initially (n = 5), and 3.6 +/- 1.6 mm Hg at follow-up (n = 5). Three-month angiographic and echocardiographic follow-up confirmed competent neovalves without paravalvular leakages.


CONCLUSIONS
After 3 months of implantation, percutaneously implanted memory nitinol valved stents demonstrated good function in the sheep.
Attmann
Tim
T
Department of Cardiovascular Surgery, Christian-Albrechts-University of Kiel, School of Medicine, Kiel, Germany.
Quaden
René
R
Jahnke
Thomas
T
Muller-Hulsbeck
Stefan
S
Boening
Andreas
A
Cremer
Jochen
J
Lutter
Georg
G
D000818:Animals; D001705:Bioprosthesis; D001794:Blood Pressure; D002417:Cattle; D004452:Echocardiography; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D011664:Pulmonary Valve / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D011859:Radiography; D012756:Sheep; D015607:Stents