Kasegawa Hitoshi, Iwasaki Kiyotaka, Kusunose Shyunsuke, Tatusta Ryota, Doi Tetsuya, Yasuda Hiroki, Umezu Mitsuo
Center for Advanced Biomedical Sciences, Waseda University, Tokyo, Japan.
J Heart Valve Dis. 2012 Jan;21(1):71-5.
The study aim was to develop a novel stentless mitral valve (SMV) and to evaluate its performance, using an original pulsatile simulator developed specifically to analyze the hydrodynamic function of the mitral valve.
The SMV developed at the authors' institution consists of two major components: a large anterior leaflet with commissures, and a small posterior leaflet. The valve is formed by suturing the leaflets (made from bovine pericardium) to a flexible (Duran) ring. The SMV, constructed with a 27 mm flexible ring, was installed into the mitral valve simulator, after which the four papillary flaps of the two leaflets were sutured to artificial papillary muscles. The artificial ventricle was driven pneumatically at a pulse rate of 70 beats/min, with a systolic fraction of 35%. The mean flow, aortic pressure, and atrial pressure were adjusted to 4.5 1/min, 120/80 mmHg, and 10 mmHg, respectively. A 27 mm mechanical valve (MEV; St. Jude Medical Inc.) was employed as a control. The hydrodynamic performance of the SMV and MEV were investigated and compared. An echo-Doppler study was also performed.
The waveforms of the SMV and MEV showed a similar pattern. The mean transvalvular flow was 4.7 +/- 0.4 1/min for the SMV, and 3.55 +/- 0.13 1/min for the MEV (p < 0.001). Mitral regurgitation was 5.07 +/- 1.15 and 3.78 +/- 0.35 ml/beat, respectively (p < 0.05). Echocardiographic data indicated that the regurgitant jet towards the left atrial model was none or trivial for the SMV, and trivial for the MEV.
Within the environment of the mitral valve simulator, the novel SMV prepared from bovine pericardium demonstrated excellent performance characteristics, and may represent a potential future alternative for bioprosthetic stented mitral valves.
本研究旨在研发一种新型无支架二尖瓣（SMV），并使用专门为分析二尖瓣流体动力学功能而开发的原始脉动模拟器评估其性能。
作者所在机构研发的SMV由两个主要部分组成：一个带有瓣叶连合的大前叶和一个小后叶。瓣膜通过将瓣叶（由牛心包制成）缝合到一个柔性（杜兰）环上形成。将构建有27毫米柔性环的SMV安装到二尖瓣模拟器中，然后将两个瓣叶的四个乳头瓣叶缝合到人工乳头肌上。人工心室以70次/分钟的脉冲频率气动驱动，收缩分数为35%。平均流量、主动脉压和心房压分别调整为4.5升/分钟、120/80毫米汞柱和10毫米汞柱。使用一个27毫米的机械瓣膜（MEV；圣犹达医疗公司）作为对照。对SMV和MEV的流体动力学性能进行了研究和比较。还进行了超声多普勒研究。
SMV和MEV的波形显示出相似的模式。SMV的平均跨瓣流量为4.7±0.4升/分钟，MEV为3.55±0.13升/分钟（p<0.001）。二尖瓣反流分别为5.07±1.15和3.78±0.35毫升/搏动（p<0.05）。超声心动图数据表明，朝向左心房模型的反流束对于SMV无或轻微，对于MEV为轻微。
在二尖瓣模拟器环境中，由牛心包制备的新型SMV表现出优异的性能特征，可能代表生物假体支架二尖瓣未来的一种潜在替代方案。
