Real-time three-dimensional trans-esophageal echocardiography in mitral valve plasty:ten cases 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 morphologic 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 patients were obtained.The images were off-line analyzed with Olab 7.0 MVQ soft.Morphologic parameters of mitral annulus and valve including circumference and area of annulus in projection plane,perimeter of annulus,area of minimal surface spanning annulus,aortic orifice 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 projection plane,area of minimal surface spanning annulus,perimeter of annulus,anterolateral to posteromedial diameter and anterior to posterior 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 anterior leaflet,angle of posterior leaflet and mitral valve coaptation index were larger than those before operation(P 0.05).3) The multiple linear regression analysis showed a significant correlation between variance of mitral valve coaptation index with total area of anterior leaflet and variance of aortic orifice to mitral plane anglethat(Y = 11.069-0.059χ 1 +0.530χ 2 in which Y was the variance of mitral valve coaptation index,χ 1 was the variance of total area of anterior leaflet,and χ 2 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.