In vivo assessment of novel stentless valve in the mitral position.
BACKGROUND
We conducted in vivo examinations of a newly designed stentless mitral valve (SMV), formed by suturing 2 leaflets with the "legs" serving as chorda tendinea, made from bovine pericardium, to a flexible ring. METHODS AND RESULTS: Seven pigs underwent implantation of the SMV constructed with a 23-mm (n=5) or 25-mm (n=2) Duran ring. Baseline echocardiography examinations were used to evaluate the annular anteroposterior diameter, and distance between the mitral annulus (MA) and papillary muscles (PMs) to determine SMV-leg length. After removing the native valve, the SMV-legs were fixed to the anterior and posterior PMs, followed by fixation of the ring to the native MA. Immediately after surgery, all animals presented none or trivial mitral regurgitation, with mean and peak trans-SMV pressure gradient values of 1.9±0.8 and 6.0±3.1 mmHg, respectively. The mean length of the SMV-leg was 19.4±3.9 mm, which correlated with the distance between anterior and posterior MA-PM (r=0.96 and 0.94, respectively, P<0.01 for both). The discrepancy between the anteroposterior diameter of the ring (outside diameter) and that of the native valve was 1.0±2.9 mm, which correlated with the trans-SMV pressure gradient (r=0.81, P=0.025).


CONCLUSIONS
In our preliminary study, the SMV demonstrated excellent diastolic inflow dynamics and closing function in vivo. Preoperative precise assessment of MV configuration may serve as a basis for selection of appropriate ring size and SMV-leg length.
Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine.
Satoshi
S
Kainuma
Hitoshi
H
Kasegawa
Shigeru
S
Miyagawa
Hiroyuki
H
Nishi
Hitoshi
H
Yaku
Shuichiro
S
Takanashi
Kazuhiro
K
Hashimoto
Yukikatsu
Y
Okada
Satoshi
S
Nakatani
Mitsuo
M
Umezu
Takashi
T
Daimon
Taichi
T
Sakaguchi
Koichi
K
Toda
Yoshiki
Y
Sawa
D000818:Animals; D001705:Bioprosthesis; D002417:Cattle; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000503:physiopathology / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000503:physiopathology / Q000601:surgery*; D013552:Swine