School of Mechanical, Medical and Process Engineering, Queensland University of Technology (QUT), 2 George St, Brisbane, QLD, 4000, Australia.
Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, 4000, Australia.
Ann Biomed Eng. 2021 Apr;49(4):1169-1182. doi: 10.1007/s10439-020-02655-1. Epub 2020 Oct 20.
Acute cerebral ischemic events and thrombosis are associated with the rupture/erosion of carotid atherosclerotic plaques. The aim of the present study was to determine the impact of calcification deposition on the wall shear stress (WSS) and stresses within the plaques using 3D fluid-structure interaction (FSI) models. Six patients with calcified carotid atherosclerosis underwent multisequence magnetic resonance imaging (MRI) and were divided into three groups according to the calcification volume. To evaluate the role of the calcification deposition on the stresses, the calcification content was replaced by lipids and arterial tissue, respectively. By comparing the results from the simulation with calcification, and when changing it to lipids there was a significant increment in the stresses at the fibrous cap (p = 0.004). Instead, by changing it to arterial tissue, there was no significant difference (p = 0.07). The calcification shapes that presented the highest stresses were thin concave arc-shaped (AS1) and thin convex arc-shaped (AS3), with mean stress values of 107 ± 54.2 and 99.6 ± 23.4 kPa, respectively. It was also observed that, the calcification shape has more influence on the level of stress than its distance to the lumen. Higher WSS values were associated with the presence of calcification. Calcification shape plays an important role in producing high stresses in the plaque. This work further clarifies the impact of calcification on plaque vulnerability.
急性脑缺血事件和血栓形成与颈动脉粥样硬化斑块的破裂/侵蚀有关。本研究旨在使用三维流固耦合（FSI）模型来确定钙化沉积对壁面剪切应力（WSS）和斑块内应力的影响。对 6 名患有钙化性颈动脉粥样硬化的患者进行了多序列磁共振成像（MRI）检查，并根据钙化体积将其分为三组。为了评估钙化沉积对应力的作用，分别用脂质和动脉组织替代钙化含量。通过比较模拟与钙化结果，以及当将钙化改变为脂质时，纤维帽处的应力显著增加（p=0.004）。相反，将其改变为动脉组织时，差异无统计学意义（p=0.07）。呈现最高应力的钙化形状为薄凹弧形（AS1）和薄凸弧形（AS3），平均应力值分别为 107±54.2kPa 和 99.6±23.4kPa。还观察到，钙化形状对压力水平的影响大于其与管腔的距离。较高的 WSS 值与钙化的存在有关。钙化形状在斑块中产生高应力方面起着重要作用。这项工作进一步阐明了钙化对斑块易损性的影响。
