Sokolis Dimitrios P
Laboratory of Biomechanics, Center of Clinical, Experimental Surgery, and Translational Research, Biomedical Research Foundation of the Academy of Athens, 4 Soranou Ephesiou Street, Athens 115 27, Greece.
J Biomech Eng. 2024 Feb 1;146(2). doi: 10.1115/1.4064146.
There is little information on the layer-specific failure properties of the adult human abdominal aorta, and there has been no quantification of postfailure damage. Infra-renal aortas were thus taken from forty-seven autopsy subjects and cut into 870 intact-wall and layer strips that underwent uni-axial-tensile testing. Intact-wall failure stress did not differ significantly (p > 0.05) from the medial value longitudinally, nor from the intimal and medial values circumferentially, which were the lowest recorded values. Intact-wall failure stretch did not differ (p > 0.05) from the medial value in either direction. Intact-wall prefailure stretch (defined as failure stretch-stretch at the initiation of the concave phase of the stress-stretch response) did not differ (p > 0.05) from the intimal and medial values, and intact-wall postfailure stretch (viz., full-rupture stretch-failure stretch) did not differ (p > 0.05) from the adventitial value since the adventitia was the last layer to rupture, being most extensible albeit under residual tension. Intact-wall failure stress and stretch declined from 20 to 60 years, explained by steady declines throughout the lifetime of their medial counterparts, implicating beyond 60 years the less age-varying failure properties of the intima under minimal residual compression. The positive correlation of postfailure stretch with age counteracted the declining failure stretch, serving as a compensatory mechanism against rupture. Hypertension, diabetes, and coronary artery disease adversely affected the intact-wall and layer-specific failure stretches while increasing stiffness.
关于成年人体腹主动脉各层特定的失效特性，相关信息较少，且尚未对失效后的损伤进行量化。因此，从47名尸检对象中获取肾下腹主动脉，并将其切成870条完整壁和分层条带，进行单轴拉伸试验。完整壁的失效应力在纵向与中层值无显著差异（p>0.05），在周向与内膜和中层值也无显著差异，这些是记录到的最低值。完整壁的失效伸长在任一方向上与中层值均无差异（p>0.05）。完整壁的失效前伸长（定义为应力-伸长响应凹相开始时的失效伸长-伸长）与内膜和中层值无差异（p>0.05），完整壁的失效后伸长（即完全破裂伸长-失效伸长）与外膜值无差异（p>0.05），因为外膜是最后破裂的层，尽管处于残余张力下但最具延展性。完整壁的失效应力和伸长从20岁到60岁呈下降趋势，这可以通过其相应中层在整个生命周期中的稳步下降来解释，这意味着60岁以后内膜在最小残余压缩下的失效特性随年龄变化较小。失效后伸长与年龄的正相关抵消了失效伸长的下降，作为一种防止破裂的补偿机制。高血压、糖尿病和冠状动脉疾病在增加硬度的同时，对完整壁和各层特定的失效伸长产生不利影响。
