10例二尖瓣成形术的经食管实时三维超声心动图研究

目的采用经食管实时三维超声心动图对二尖瓣成形术前后二尖瓣环及瓣叶三维结构特征进行定量对比研究,确定评价二尖瓣成形术治疗效果的主要形态学指标和关键影响因素。方法 10例二尖瓣脱垂患者在全麻下于二尖瓣成形术前后行经食管实时三维超声心动图(Philips IE33超声心动图成像仪、X7-2t探头)扫查。分别采集二尖瓣环与瓣叶结构的全容积三维动态超声图像以及二尖瓣反流束的彩色多普勒实时三维动态超声图像。运用Qlab7.0MVQ软件对图像进行脱机分析,获得二尖瓣瓣环在二维投影平面中的面积与周长、瓣环的最小三维面积与三维周长、主动脉口二尖瓣环平面夹角、二尖瓣的暴露面积、前叶面积、后叶面积、脱垂高度、脱垂容积等二尖瓣环及瓣叶的各项形态学参数测值,计算二尖瓣对合指数及二尖瓣环与瓣叶各参数在二尖瓣成形术前后的变化值,并进行多元线性回归分析。结果①二尖瓣成形术后,二尖瓣环在二维投影平面中的面积和周长,瓣环的最小三维面积和三维周长,瓣环的前外侧至后内侧直径、前后直径、环的高度及环高度与前外侧至后内侧直径的比率均明显小于术前(P<0.01)。②二尖瓣成形术后,二尖瓣叶的暴露面积、前叶面积、后叶面积、脱垂高度、脱垂容积、前外侧至后内侧接合直径、前外侧至后内侧接合在投影平面内的弧长、投影在近似小叶表面的前外侧至后内侧的接合弧长及非平面小叶角度均明显小于术前(P<0.05),二尖瓣前叶角度、后叶角度及二尖瓣对合指数均明显大于术前(P<0.05)。③将二尖瓣成形术前后二尖瓣环与瓣叶各项形态学参数的变化值与二尖瓣成形术前后二尖瓣对合指数的变化值进行多元线性回归分析,建立多元线性回归模型:Y=11.069-0.059χ1+0.530χ2(Y:二尖瓣成形术前后二尖瓣对合指数的变化值,χ1:二尖瓣成形术前后二尖瓣前叶面积变化值,χ2:二尖瓣成形术前后主动脉口二尖瓣环平面间角度变化值,P=0.002)。结论经食管实时三维超声心动图为定量评价二尖瓣环与瓣叶的三维结构提供了有效的技术手段。二尖瓣对合指数作为评价二尖瓣成形术效果最重要的指标可以通过经食管实时三维超声心动图得到准确测量。二尖瓣成形术要获得较大的对合指数,应尽量保存二尖瓣前叶的面积;二尖瓣成形术对主动脉口二尖瓣环平面间角度的改变应在确保二尖瓣有效对合指数的前提下尽可能使其接近正常的解剖角度。

Real-time three-dimensional trans-esophageal echocardiography in mitral valve plasty:ten ca-ses report

Objective To quantitatively compare three dimensional constructions of mitral annulus and valve before and after mitral valve plasty with real-time three-dimensional trans-esophageal echocardiography （RT-3DTEE） ,thereby ,to identify the best mor- phologic parameter for evaluating effect of mitral valve plasty and its main influential factors. Methods Ten patients with mitral valve prolapse underwent examination by RT-3DTEE （Philips IE33, X7-2t） before and after mitral valve plasty under general anesthesia. Full-volume 3D dynamic images of mitral annulus and valve, and color real-time 3D dynamic images of mitral regurgitation in all pa- tients were obtained. The images were off-line analyzed with Olab 7.0 MVQ soft. Morphologic parameters of mitral annulus and valve in- eluding circumference and area of annulus in projection plane, perimeter of annulus, area of minimal surface spanning annulus, aortic or- ifice to mitral plane angle, exposed area of leaflet, total area of anterior leaflet, total area of posterior leaflet, maximal prolapse height, volume of leaflet prolapse were calculated. Then, mitral valve coaptation index and variances of all morphologic parameters before and after operation were analyzed with multivariate linear regression model. Results 1 ） The circumference and area of annulus in projec- tion plane, area of minimal surface spanning annulus, perimeter of annulus, anterolateral to posteromedial diameter and anterior to poste- rior diameter of annulus, annulus height and ratio of annulus height to commissural diameter became smaller after mitral valve plasty as compared with these parameters before operation （P 〈 0.01 ）. 2） The exposed area of leaflet, total area of anterior leaflet, total area of posterior leaflet, maximal prolapse height, volume of leaflet prolapse, commissure to commissure diameter,length of coaptation in projection plane, length of coaptation projected to approximate leaflets surface and non-planar angle of leaflets after surgery also became smaller compared to those before operation （ P 〈 0.05 ）. However, angle of an- terior leaflet, angle of posterior leaflet and mitral valve coaptation in- dex were larger than those before operation （ P 〉 0.05 ）. 3 ） The mul- tiple linear regression analysis showed a significant correlation be- tween variance of mitral valve coaptation index with total area of ante-rior leaflet and variance of aortic orifice to mitral plane anglethat （ Y = 11. 069-0. 059）（1 ＋0. 530）（2 in which Y was the variance of mitral valve coaptation index,x1 was the variance of total area of anterior leaflet, andx2 was the variance of aortic orifice to mitral plane angle, P = 0.002）. Conclusions RT-3DTEE is an effective technique to evaluate quantitatively 3D construction of mitral annulus and valve. The mitral valve coaptation index is one of the most important parameters in estimation of the effect of mitral valve plasty. The index can be accurately determined by RT-3DTEE. The total area of anterior leaflet should to be maintained as large as possible in order to obtain optimal coaptation index. The change of angle of aortic orifice to mitral plane should only be performed under the premise of optimal mitral valve coaptation index. The angle should be adjusted to its normal anatomic angle as best as possible.