Morrel William G, Ge Liang, Zhang Zhihong, Grossi Eugene A, Guccione Julius M, Ratcliffe Mark B
J Heart Valve Dis. 2014 Nov;23(6):727-34.
Mitral annuloplasty (MA) devices are available in different shapes and sizes, but the preferred shape and size are unclear.
A previously described and validated finite element (FE) model of the left ventricle (LV) with mitral valve (MV) based on magnetic resonance imaging and three-dimensional echocardiography images from a patient with posterior leaflet (PL; P2) prolapse was used in this study. FE models of MA devices with different shapes (flat partial, shallow saddle, pronounced saddle) and sizes (36-30) were created. Virtual leaflet resection + MA with each shape and size were simulated. Leaflet geometry, stresses in the leaflets and base of the LV, and forces in the chordae and MA sutures were calculated.
All MA shapes increased the mitral coaptation length, reduced the elevated PL stress at end-diastole (ED) and end-systole (ES) that occurred after leaflet resection, and reduced anterior leaflet (AL) stress at ES. MA devices of all shapes and sizes modestly reduced myofiber stress at the LV base in ED and ES. In general, saddle-shaped devices had the greatest effect.
All MA shapes increased coaptation length and reduced mitral leaflet stress and myofiber stress in the base of the LV. an additional reduction in MA size further increased coaptation length and reduced leaflet and myofiber stress. In general, saddle-shaped devices had the greatest effect.
二尖瓣环成形术（MA）装置有不同的形状和尺寸，但最佳形状和尺寸尚不清楚。
本研究使用了一个先前描述并验证的基于磁共振成像和三维超声心动图图像构建的左心室（LV）合并二尖瓣（MV）的有限元（FE）模型，该图像来自一名后叶（PL；P2）脱垂患者。创建了不同形状（扁平部分型、浅鞍型、明显鞍型）和尺寸（36 - 30）的MA装置的有限元模型。模拟了每种形状和尺寸的虚拟瓣叶切除术 + MA。计算了瓣叶几何形状、瓣叶和左心室基部的应力以及腱索和MA缝线中的力。
所有MA形状均增加了二尖瓣瓣叶对合长度，降低了瓣叶切除后舒张末期（ED）和收缩末期（ES）升高的PL应力，并降低了ES时前叶（AL）应力。所有形状和尺寸的MA装置在ED和ES时均适度降低了左心室基部的肌纤维应力。总体而言，鞍形装置效果最佳。
所有MA形状均增加了瓣叶对合长度，降低了二尖瓣瓣叶应力和左心室基部的肌纤维应力。MA尺寸的进一步减小进一步增加了瓣叶对合长度并降低了瓣叶和肌纤维应力。总体而言，鞍形装置效果最佳。
