Comparison of Mechanical Properties of Human Ascending Aorta and Aortic Sinuses
Comparison of Mechanical Properties of Human Ascending Aorta and Aortic Sinuses
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DOI：
10.1016/j.athoracsur.2011.08.002
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发表时间：
2012-01-01
影响因子：
4.6
通讯作者：
Tseng, Elaine E.
中科院分区：
文献类型：
--
作者：
Azadani, Ali N.;Chitsaz, Sam;Tseng, Elaine E.
背景资料。计算主动脉根部的有限元模型以前使用升主动脉的材料特性来描述升主动脉窦和升主动脉。我们以前已经在猪的升主动脉和窦道中发现了显著的物质特性差异。然而，目前尚不清楚人类是否存在这些地区性物质特性差异。本研究的主要目的是研究新鲜人体升主动脉和主动脉窦的生物力学特性，并比较这两个区域的非线性材料特性。从加州移植供者网络(Oakland，CA)获得的新鲜人主动脉根部标本在收获后24小时内接受了位移控制的等轴拉伸测试。记录的应力-应变数据被用来推导每个区域的应变能函数。通过组织硬度量化组织行为，并在生理应力水平上直接比较主动脉根部不同区域的组织行为。在拉伸试验中，所有区域在周向和纵向都表现出对应变的非线性响应。升主动脉前后区之间以及三个窦道之间的组织硬度在两个方向上没有显著差异。然而，我们的结果表明，在生理应力范围内，人的升主动脉在周向和纵向上都明显比主动脉窦顺应性强。人升主动脉和升主动脉窦在材料和结构上存在显著差异。在用于评估结构性主动脉根部疾病治疗的计算模型中，应采用特定于区域的材料特性。(Ann Thorac Surg 2012；93：87-94)(C)2012年，胸外科学会
Background. Computational finite element models of the aortic root have previously used material properties of the ascending aorta to describe both aortic sinuses and ascending aorta. We have previously demonstrated significant material property differences between ascending aorta and sinuses in pigs. However, it is unknown whether these regional material property differences exist in humans. The main objective of this study was to investigate biomechanics of fresh human ascending aorta and aortic sinuses and compare nonlinear material properties of these regions.Methods. Fresh human aortic root specimens obtained from the California Transplant Donor Network (Oakland, CA) were subjected to displacement-controlled equibiaxial stretch testing within 24 hours of harvest. Stress-strain data recorded were used to derive strain energy functions for each region. Tissue behavior was quantified by tissue stiffness and a direct comparison was made between different regions of aortic root at physiologic stress levels.Results. All regions demonstrated a nonlinear response to strain during stretch testing in both circumferential and longitudinal directions. No significant difference in tissue stiffness was found between anterior and posterior regions of the ascending aorta or among the three sinuses in both directions. However, our results demonstrated that human ascending aorta is significantly more compliant than aortic sinuses in both circumferential and longitudinal directions within the physiologic stress range.Conclusions. Significant material and structural differences were observed between human ascending aorta and aortic sinuses. Regionally specific material properties should be employed in computational models used to assess treatments of structural aortic root disease. (Ann Thorac Surg 2012;93:87-94) (C) 2012 by The Society of Thoracic Surgeons