Department of Mechanical Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin-si, Gyeonggi-do, 17058, South Korea.
Med Biol Eng Comput. 2018 Nov;56(11):2003-2013. doi: 10.1007/s11517-018-1839-7. Epub 2018 May 8.
To investigate the effect of longitudinal variations of cap thickness and tissue properties on wall stresses and strains along the atherosclerotic stenosis, stenotic plaque models (uniformly thick, distally thickened, homogenous, and distally stiffened) were constructed and subjected to computational stress analyses with due consideration of fluid-structure interactions (FSI). The analysis considered three different cap thicknesses-45, 65, and 200 μm-and tissue properties-soft, fibrous, and hard. The maximum peak cap stress (PCS) and strain were observed in the upstream throat section and demonstrated increases of the order of 345 and 190%, respectively, as the cap thickness was reduced from 200 to 45 μm in uniformly thick models. Distal stiffening increased PCS in the downstream region; however, the overall effect of this increase was rather small. Distal thickening did not affect maximum PCS and strain values for cap thicknesses exceeding 65 μm; however, a noticeable increase in maximum PCS and corresponding longitudinal variation (or spatial gradient) in stress was observed in the very thin (45-μm-thick) cap. It was, therefore, inferred that existence of a rather thin upstream cap demonstrating distal cap thickening indicates an increased risk of plaque progression and rupture. Graphical Abstract ᅟ.
为了研究斑块帽厚度和组织性质的纵向变化对动脉粥样硬化狭窄处管壁应力和应变的影响，构建了狭窄斑块模型（均匀增厚、远侧增厚、均质和远侧变硬），并考虑了流固耦合（FSI）进行了计算应力分析。该分析考虑了三种不同的帽厚度——45μm、65μm 和 200μm——以及组织特性——软、纤维和硬。最大峰值帽应力（PCS）和应变出现在上游喉区，在均匀增厚模型中，帽厚度从 200μm 减小到 45μm 时，分别增加了约 345%和 190%。远侧变硬增加了下游区域的 PCS；然而，这种增加的整体影响相当小。远侧增厚不会影响帽厚度超过 65μm 时的最大 PCS 和应变值；然而，在非常薄的（45μm 厚）帽中观察到最大 PCS 和相应的纵向变化（或空间梯度）明显增加。因此，可以推断，存在一个显示远侧帽增厚的相当薄的上游帽表明斑块进展和破裂的风险增加。
