Quantification and comparison of the mechanical properties of four human cardiac valves
Quantification and comparison of the mechanical properties of four human cardiac valves
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DOI：
10.1016/j.actbio.2017.03.026
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发表时间：
2017-04-24
影响因子：
9.7
通讯作者：
Sun, Wei
中科院分区：
文献类型：
--
作者：
Thuy Pham;Sulejmani, Fatiesa;Sun, Wei
目的：虽然四个主要瓣膜（二尖瓣（MV）、主动脉瓣（AV）、三尖瓣（TV）和肺动脉瓣（PV））具有相同的允许心脏内单向流动的能力，但它们经历不同的负荷条件；因此，它们表现出彼此不同的结构完整性。大多数心脏瓣膜力学研究主要针对 MV 和 AV 或单个瓣膜进行，但没有量化和比较来自与心血管疾病死亡无关的同一年龄患者群体的四个瓣膜的机械和结构特性。方法：从 12 具死亡与心血管疾病无关的人类尸体（70.1+/-3.7 岁）中切除总共 114 个瓣叶样本。通过平面双轴机械测试和组织学方法来表征组织机械和结构特性。然后将实验数据与Fung型本构模型进行拟合。结果：四个瓣膜在厚度、各向异性程度和刚度方面存在显着差异。左心的小叶（AV 小叶和二尖瓣前叶，AML）比右心的小叶明显更硬且顺应性较差。 TV 传单的延展性最强且各向同性，而 AML 和 AV 传单的延展性最差且各向异性最强。年龄在降低小叶刚度和延展性方面发挥着重要作用，在老年群体（65 岁及以上）的小叶样本中观察到几乎伸直的胶原纤维。结论：114 个人类瓣叶样本的结果不仅提供了老年人类心脏瓣膜机械特性的基线量化，而且还提供了对四种瓣膜之间年龄依赖性差异的更好理解。希望本研究中收集的实验数据和相关的本构模型能够促进未来对瓣膜疾病、治疗和介入器械的开发的研究。 意义声明大多数心脏瓣膜力学研究主要针对二尖瓣和主动脉瓣或单个瓣膜进行，但没有量化和比较来自相同相对健康的老年患者群体的四个瓣膜的机械和结构特性。在这项研究中，对来自 12 具尸体心脏的 114 个主动脉瓣、二尖瓣、肺动脉瓣和三尖瓣瓣叶的机械和微观结构特性进行了机械测试、分析和比较。我们的结果不仅提供了老年人类瓣膜机械性能的基线量化，而且患者的年龄范围（51-87 岁）也提供了对四种瓣膜之间年龄依赖性差异的更好理解。希望所获得的实验数据和相关本构参数能够促进瓣膜疾病的研究、治疗和介入器械的开发。 (C) 2017 Acta Materialia Inc. 由 Elsevier Ltd 出版。保留所有权利。
Objective: Although having the same ability to permit unidirectional flow within the heart, the four main valves the mitral valve (MV), aortic (AV), tricuspid (TV) and pulmonary (PV) valves-experience different loading conditions; thus, they exhibit different structural integrity from one another. Most research on heart valve mechanics have been conducted mainly on MV and AV or an individual valve, but none quantify and compare the mechanical and structural properties among the four valves from the same aged patient population whose death was unrelated to cardiovascular disease. Methods: A total of 114 valve leaflet samples were excised from 12 human cadavers whose death was unrelated to cardiovascular disease (70.1 +/- 3.7 years old). Tissue mechanical and structural properties were characterized by planar biaxial mechanical testing and histological methods. The experimental data were then fitted with a Fung-type constitutive model. Results: The four valves differed substantially in thickness, degree of anisotropy, and stiffness. The leaflets of the left heart (the AV leaflets and the anterior mitral leaflets, AML) were significantly stiffer and less compliant than their counterparts in the right heart. TV leaflets were the most extensible and isotropic, while AML and AV leaflets were the least extensible and the most anisotropic. Age plays a significant role in the reduction of leaflet stiffness and extensibility with nearly straightened collagen fibers observed in the leaflet samples from elderly groups (65 years and older). Conclusions: Results from 114 human leaflet samples not only provided a baseline quantification of the mechanical properties of aged human cardiac valves, but also offered a better understanding of the age-dependent differences among the four valves. It is hoped that the experimental data collected and the associated constitutive models in this study can facilitate future studies of valve diseases, treatments and the development of interventional devices.Statement of SignificanceMost research on heart valve mechanics have been conducted mainly on mitral and aortic valves or an individual valve, but none quantify and compare the mechanical and structural properties among the four valves from the same relatively healthy elderly patient population. In this study, the mechanical and microstructural properties of 114 leaflets of aortic, mitral, pulmonary and tricuspid valves from 12 human cadaver hearts were mechanically tested, analyzed and compared. Our results not only provided a baseline quantification of the mechanical properties of aged human valves, but a age range between patients (51-87 years) also offers a better understanding of the age-dependent differences among the four valves. It is hoped that the obtained experimental data and associated constitutive parameters can facilitate studies of valve diseases, treatments and the development of interventional devices. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.