Toma Milan, Bloodworth Charles H, Einstein Daniel R, Pierce Eric L, Cochran Richard P, Yoganathan Ajit P, Kunzelman Karyn S
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Technology Enterprise Park, Suite 200, 387 Technology Circle, Atlanta, GA, 30313-2412, USA.
Computational Biology and Bioinformatics, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
Biomech Model Mechanobiol. 2016 Dec;15(6):1619-1630. doi: 10.1007/s10237-016-0786-1. Epub 2016 Apr 19.
The diversity of mitral valve (MV) geometries and multitude of surgical options for correction of MV diseases necessitates the use of computational modeling. Numerical simulations of the MV would allow surgeons and engineers to evaluate repairs, devices, procedures, and concepts before performing them and before moving on to more costly testing modalities. Constructing, tuning, and validating these models rely upon extensive in vitro characterization of valve structure, function, and response to change due to diseases. Micro-computed tomography ([Formula: see text]CT) allows for unmatched spatial resolution for soft tissue imaging. However, it is still technically challenging to obtain an accurate geometry of the diastolic MV. We discuss here the development of a novel technique for treating MV specimens with glutaraldehyde fixative in order to minimize geometric distortions in preparation for [Formula: see text]CT scanning. The technique provides a resulting MV geometry which is significantly more detailed in chordal structure, accurate in leaflet shape, and closer to its physiological diastolic geometry. In this paper, computational fluid-structure interaction (FSI) simulations are used to show the importance of more detailed subject-specific MV geometry with 3D chordal structure to simulate a proper closure validated against [Formula: see text]CT images of the closed valve. Two computational models, before and after use of the aforementioned technique, are used to simulate closure of the MV.
二尖瓣(MV)几何形状的多样性以及用于纠正MV疾病的多种手术选择使得计算建模成为必要。MV的数值模拟将使外科医生和工程师能够在进行修复、使用装置、实施手术和验证概念之前,以及在转向成本更高的测试方式之前对其进行评估。构建、调整和验证这些模型依赖于对瓣膜结构、功能以及疾病引起的变化反应进行广泛的体外表征。微型计算机断层扫描(μCT)在软组织成像方面具有无与伦比的空间分辨率。然而,获得舒张期MV的精确几何形状在技术上仍然具有挑战性。我们在此讨论一种用戊二醛固定剂处理MV标本的新技术的开发,以便在为μCT扫描做准备时尽量减少几何变形。该技术提供的MV几何形状在弦结构方面明显更详细,小叶形状更准确,并且更接近其生理舒张期几何形状。在本文中,计算流体结构相互作用(FSI)模拟用于展示具有三维弦结构的更详细的特定个体MV几何形状对于模拟正确关闭的重要性,该关闭过程已根据关闭瓣膜的μCT图像进行了验证。使用上述技术前后的两个计算模型用于模拟MV的关闭。