二尖瓣成行术后二尖瓣特征参数的三维量化分析

Quantitative assessment of mitral valve apparatus before and after mitral valve surgery by real-time three-dimentional echocardiography

目的量化分析二尖瓣成形术前、术后二尖瓣特征参数,明确二尖瓣成形术后残留二尖瓣反流(MR)的发生机制。方法选取行二尖瓣成形术患儿30例,根据患儿术后MR改善程度,分为反流改善组与未改善组,量化分析和比较患儿二尖瓣装置三维参数术前、术后的改变。结果二尖瓣成形术后,MR改善组与MR未改善组相比,瓣环扩大程度均较术前改善,差异有统计学意义(P<0.05);后瓣活动度幅度、前后组乳头肌至瓣环的空间三维距离、前后组乳头肌之间的空间距离、乳头肌与瓣环夹角、左室容量及射血分数等参数,MR改善组较术前明显改善(P<0.01),而MR未改善组,除后瓣活动度外,其余参数术前、术后差异无统计学意义(P>0.05)。结论 MR改善组患儿术后二尖瓣装置参数较术前有明显好转,而MR未改善组除二尖瓣环大小与瓣叶活动度较术前好转外,乳头肌位置、瓣下牵拉力、左室功能等无明显改变,而这些因素可能是术后残余反流的关键所在。

Objectives To evaluate the mechanism of mitral regurgitation after mitral valve surgery by quantitative assessment of mitral valve three-dimensional parameters using real-time three-dimensional echocardiography (RT-3DE). Me-thods According to the improved degree of mitral regurgitation (MR), 30 children were divided into two groups after mitral valve repair:MR improved (I) group and residual MR (II) group. And the pre-operative 3-DE parameters were compared with post-operative parameters in two groups respectively. Results In group I, three dimensional parameters, including mitral valve annular area in end-systole and end-dilate (AA1, AA2), PM papillary muscle annular distance (AL-A), AL papillary muscle annular distance (PM-A), inter-papillary distance (PM-AL), the anterior leaflet and posterior leaflet tethering angles (a1, a2, argAL-C-PM), left ventricular volume end-systole and end-dilate (LVEDV, LVESV) were significantly improved after surgery (P<0.05) while the parameters PM-A, PM-AL, argAL-C-PM, LVEDV, LVESV and left ventricular ejection fraction (LVEF) were not significantly changed after surgery in group II, except for the parameters AA1, AA2 and a2 (P>0.05). Conclusions Most of the mitral valve parameters were much better in group I after surgery. However, the malformation of papillary appa-ratus, leaflet tethering strength and left ventricular function were unchanged in group II, which may be the key mechanism of mitral regurgitation after surgery.