Group of Structural Mechanics and Materials Modelling, Aragón Institute of Engineering Research, University of Zaragoza, Campus Río Ebro, María de Luna 3, Zaragoza, Spain.
Med Eng Phys. 2011 Jul;33(6):665-76. doi: 10.1016/j.medengphy.2011.01.016. Epub 2011 Mar 2.
The present study focusses on the determination, comparison and constitutive modelling of the passive mechanical properties of the swine carotid artery over very long stretches in both proximal and distal regions. Special attention is paid to the histological and mechanical variations of these properties depending on the proximity to the heart. The results can have clinical relevance, especially in the research field of intravascular device design. Before the final clinical trials on humans, research in the vascular area is conducted on animal models, swine being the most common due to the similarities between the human and swine cardiovascular systems as well as the fact that the swine size is suitable for testing devices, in this case endovascular carotid systems. The design of devices usually involves numerical techniques, and an important feature is the appropriate modelling of the mechanical properties of the vessel. Fourteen carotid swine arteries were harvested just after sacrifice and cyclic uniaxial tension tests in longitudinal and circumferential directions were performed for distal and proximal samples. The stress-stretch curves obtained were fitted with a hyperelastic anisotropic model. Stress-free configuration states were also analyzed. Finally, human and swine samples were processed in a histological laboratory and images were used to quantify their microconstituents. The statistical analysis revealed significant differences between the mechanical behavior of proximal and distal locations in the circumferential but not in the longitudinal direction. Circumferential direction samples show clear differences both in residual stretches and tensile curves between the two locations, while the features of longitudinal specimens are independent of the axial position. The statistical analysis provides significant evidence of changes depending on the position of the sample, mainly in elastin and SMC quantification.
本研究专注于确定、比较和构建猪颈总动脉在近端和远端非常长的节段的被动机械性能，并特别关注这些性能随距离心脏远近的组织学和力学变化。该结果可能具有临床意义，特别是在血管内装置设计的研究领域。在对人体进行最终临床试验之前，在动物模型中进行血管领域的研究，由于人类和猪心血管系统之间的相似性以及猪的大小适合测试装置，特别是血管内颈动脉系统，因此猪是最常见的模型。装置的设计通常涉及数值技术，而一个重要的特征是对血管机械性能的适当建模。在处死猪后立即采集了 14 个颈总动脉，并对远段和近段样本进行了循环单轴拉伸测试，测试方向分别为纵向和周向。获得的应力-应变曲线采用超弹性各向异性模型拟合。还分析了无应力配置状态。最后，在组织学实验室对人和猪的样本进行处理，并使用图像对其微观成分进行定量分析。统计分析显示，在周向而非纵向方向，近段和远段的力学行为存在显著差异。周向方向的样本在两个位置的残余伸长和拉伸曲线上都存在明显差异，而纵向样本的特征与轴向位置无关。统计分析提供了明显的证据，表明位置的变化取决于样本的位置，主要表现在弹性蛋白和 SMC 定量方面。
