Measurement of intramural stress and strain distributions in the atherosclerotic arteries considering the complexity of the lesion

考虑病变的复杂性，测量动脉粥样硬化动脉的壁内应力和应变分布

基本信息

批准号：
11680834
负责人：
MATSUMOTO Takeo
金额：
$ 2.37万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

To reveal the effects of mechanical factors on the initiation and progression of atherosclerosis, it is important to know the stress and strain distribution in the atherosclerotic lesions as well as the effects of blood flow on the endothelial cells. In this 2-year project, we experimentally induced atherosclerotic lesions in the rabbit thoracic aortas and studied the mechanical environment of the atherosclerotic lesions by measuring their local mechanical properties and local defomation of the aortas during inflation. We first measured local elastic modulus by a pipette aspiration method and studied the relationship between the modulus and the histology quantitatively to find that the atherosclerotic tissue became softer than the normal tissue at the initial stage of the lesion, then became stiffer with the appearance of the smooth muscle cells and calcified tissues. Next, we measured the deformation of the tubular specimen of the aortas during inflation as follows : We made four fine needles penetrate through the wall at an angular interval of about 90゜ as markers and observed the displacement of the needles during inflation from an end of the specimen. Local deformations of the wall were obtained at four circumferential segments held with the two adjacent needles. Strain referring to the stress-free state was obtained for each segment. The strain was not uniform among the segments in the atherosclerotic aorta. The difference among the segments tended to increase with the progression of the disease. Similar measurement performed for human coronary arteries indicated that the segment with thicker plaque had smaller strain. These results indicate that atherosclerotic arteries show marked heterogeneity. Local measurement is indispensable to reveal the mechanical environment of atherosclerotic lesions.

为了揭示机械因素对动脉粥样硬化的主动性和进展的影响，重要的是要了解动脉粥样硬化病变中的应力和应变分布以及血流对内皮细胞的影响。在这个为期两年的项目中，我们通过实验性地诱导了兔胸动物中的动脉粥样硬化病变，并通过测量通胀期间主动脉的局部机械性能和主动脉的局部缺陷来研究动脉粥样硬化病变的机械环境。我们首先通过移液器抽吸法测量了局部弹性模量，并在数量上研究了模量与组织学之间的关系，以发现在病变的初始阶段，动脉粥样硬化组织变得比正常组织柔和，然后随着平滑肌的外观和计算的组织而变得僵硬。接下来，我们在通货膨胀期间测量了主动脉的管状标本的变形，如下所示：我们使四个细针头以约90°的角度穿透壁穿透了标记，并观察到从标本末端从通货膨胀的过程中置换了针头的位移。壁的局部变形是在与两个相邻针的四个圆周段处获得的。每个段都获得了参考无应力状态的应变。在动脉粥样硬化主动脉中的各个段中，该菌株并不均匀。这些细分市场之间的差异往往随疾病的发展而增加。对人冠状动脉进行的类似测量表明，斑块较厚的片段的应变较小。这些结果表明，动脉粥样硬化的动脉显示出明显的异质性。局部测量是必不可少的，以揭示动脉粥样硬化病变的机械环境。