Ex Vivo Methods for Informing Computational Models of the Mitral Valve
Ex Vivo Methods for Informing Computational Models of the Mitral Valve
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DOI：
10.1007/s10439-016-1734-z
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发表时间：
2017-02-01
影响因子：
3.8
通讯作者：
Yoganathan, Ajit P.
中科院分区：
文献类型：
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作者：
Bloodworth, Charles H.;Pierce, Eric L.;Yoganathan, Ajit P.
二尖瓣 (MV) 的计算模型对于确定最佳 MV 修复技术和复发性二尖瓣反流风险具有潜在的应用。为这些模型提供信息的两个关键问题是（1）模型性能对输入几何形状精度的敏感性，以及（2）获取全面的数据集，可以根据这些数据集在临床相关的几何形状中验证模拟。为了解决第一个问题，体外微型计算机断层扫描 (microCT) 用于以高分辨率（类似于 40 微米体素大小）对 MV 进行成像。由于 MV 在静态成像过程中明显变形，因此在 microCT 之前使用戊二醛固定。固定后，MV 小叶变形明显更小 (p < 0.005)，并且弦树的细节明显更大。为了解决第二个问题，左心模拟器被设计用于重现功能性二尖瓣反流和后续修复后体内观察到的 MV 几何扰动，并保持与 microCT 的兼容性。通过对各个状态（健康、患病和修复）的个体切除绵羊 MV（n = 5）进行排列，并在每个状态下使用 microCT 进行成像，生成了一个全面的数据集。使用该数据集，构建和验证高保真 MV 生物力学模型的工作正在进行中。这些模型将寻求将 MV 功能与临床相关状态联系起来。
Computational modeling of the mitral valve (MV) has potential applications for determining optimal MV repair techniques and risk of recurrent mitral regurgitation. Two key concerns for informing these models are (1) sensitivity of model performance to the accuracy of the input geometry, and, (2) acquisition of comprehensive data sets against which the simulation can be validated across clinically relevant geometries. Addressing the first concern, ex vivo micro-computed tomography (microCT) was used to image MVs at high resolution (similar to 40 micron voxel size). Because MVs distorted substantially during static imaging, glutaraldehyde fixation was used prior to microCT. After fixation, MV leaflet distortions were significantly smaller (p < 0.005), and detail of the chordal tree was appreciably greater. Addressing the second concern, a left heart simulator was designed to reproduce MV geometric perturbations seen in vivo in functional mitral regurgitation and after subsequent repair, and maintain compatibility with microCT. By permuting individual excised ovine MVs (n = 5) through each state (healthy, diseased and repaired), and imaging with microCT in each state, a comprehensive data set was produced. Using this data set, work is ongoing to construct and validate high-fidelity MV biomechanical models. These models will seek to link MV function across clinically relevant states.