目的 研究支架介入在不同充气压力下对病变血管壁力学环境的影响。方法 使用高分辨率MRI获得含有脂质斑块和钙化斑块的颈动脉模型,通过有限元软件构建体内血管-支架两者之间相互作用的力学模型,数值模拟分析不同充气压力(909、1212和15 15kPa)作用下的血管壁及斑块的Von Mises应力分布。结果 随着充气压力的增大,血管壁与支架接触内表面的Von Mises应力逐渐增大。在高充气压力作用下支架撑开后,脂质斑块区域会产生严重的应力集中现象;而在不同充气压力作用下,钙化斑块区域Von Mises应力分布差异很小。结论 较大充气压力作用支架撑开后将给血管壁和脂质斑块带来较大伤害,可能会引发支架后期失效。研究结果可为支架术充气压力的选择以及支架植入后斑块稳定性的预估提供临床参考。
Objective To investigate the effects of inflation pressures on mechanical environment of pathological carotid after stent implantation. Methods The carotid artery models with lipid and calcified plaques were constructed based on high-resolution MRI images. The artery-stent interaction model was developed in the finite element software. Based on the models, the von Mises stress distributions on the vascular wall and plague under 3 different inflation pressures (909, 1212 and 1515 kPa) were simulated. Results High inflation pressure would induce large Von Mises stress on the artery-stent interface. Moreover, the stress on the lipid plaque increased significantly with the increase of inflation pressure. However, the differences in stress distributions on the calcified plaque were very small under different inflation pressure. Conclusions Higher inflation pressure may severely damage the lipid plaque and artery-stent interface after stenting, which will contribute to the failure of stent. This research finding may provide clinical guidance for the selection of inflation pressure for arterial stent deployment and the assessment of plague stability after stent implantation.