Description of regional mitral annular nonplanarity in healthy human subjects: A novel methodology
Description of regional mitral annular nonplanarity in healthy human subjects: A novel methodology
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DOI：
10.1016/j.jtcvs.2007.04.001
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发表时间：
2007-09-01
影响因子：
6
通讯作者：
Gorman, Joseph H., III
中科院分区：
文献类型：
--
作者：
Ryan, Liam P.;Jackson, Benjamin M.;Gorman, Joseph H., III
目的：有限元分析表明，二尖瓣环的非平面形状减小了二尖瓣叶的应力。因此，假设用保持环状结构非平面形状的环状成形器进行修复可以提高修复的耐久性。虽然二尖瓣环的整体非平面性已经得到了充分的描述，但这种环的设计需要对区域环几何形状的定量描述。利用实时三维超声心动图结合现有的图像处理软件，开发了一种描述二尖瓣环局部几何形状的方法，并将其应用于正常人二尖瓣环的表征。方法：对5名健康志愿者进行二尖瓣成像和实时三维超声心动图。结果：所有病例的环高/连合宽度比均在前环的中点最大。这些值平均为26%+/-3.1%，而中后环平均为18%+/-3.0%。连合宽度平均为35.2±6.0 mm。虽然观察到了明显的空间异质性，但当归一化到连合宽度时，在给定旋转位置的区域环高度在受试者中是高度保守的。结论：这些定量成像和分析技术表明，正常人体二尖瓣环的非平面性具有区域性异质性，它们建立了一种在区域水平上描述二尖瓣环几何形状的方法。随着更广泛的应用，这些技术可以用来描述病理性瓣环的几何形状和优化二尖瓣成形术装置的设计。
Objective: Finite-element analysis demonstrates that the nonplanar shape of the mitral annulus diminishes mitral leaflet stress. It has therefore been postulated that repair with annuloplasty rings that maintain the nonplanar shape of the annulus could increase repair durability. Although the global nonplanarity of the mitral annulus has been adequately characterized, design of such a ring requires a quantitative description of regional annular geometry. By using real-time 3-dimensional echocardiography in conjunction with available image processing software, we developed a methodology for describing regional annular geometry and applied it to the characterization of the normal human mitral annulus.Methods: Five healthy volunteers underwent mitral valve imaging with real-time 3-dimensional echocardiography. Regional annular height was calculated at 36 evenly spaced intervals.Results: Maximal annular height/commissural width ratio was found to occur at the midpoint of the anterior annulus in all cases. These values averaged 26% +/- 3.1%, whereas those for the midposterior annulus averaged 18% +/- 3.0%. The average commissural width was 35.2 +/- 6.0 mm. Although substantial spatial heterogeneity was observed, regional annular height at a given rotational position was highly conserved among subjects when normalized to commissural width.Conclusions: These quantitative imaging and analytic techniques demonstrate that the normal human mitral annulus is regionally heterogeneous in its nonplanarity, and they establish a means of describing annular geometry at a regional level. With wider application, these techniques may be used both to characterize pathologic annular geometry and to optimize the design of mitral valve annuloplasty devices.