斑块偏心率对可降解聚乳酸支架植入狭窄血管的影响

目的研究支架在植入狭窄血管后,斑块偏心率对支架性能以及血管和斑块应力分布的影响。方法构建支架和理想化狭窄血管模型,赋予斑块4种不同偏心率(0%、20%、40%、60%),采用有限元方法分析支架扩张至目标位移时,支架的径向回弹率和轴向缩短率、血管和斑块的应力变化情况。结果随着斑块偏心率增加,支架的径向回弹率和轴向缩短率均逐渐增大。同时,血管和斑块的应力也呈递增趋势,且高应力区域都逐渐靠近狭窄侧一端,斑块最大von Mises等效应力远大于动脉。结论斑块偏心率对支架性能以及狭窄血管的应力分布有一定影响。在支架设计中,应对斑块的几何形状予与考虑,以改善支架在介入治疗中的临床效果。

Effects of Plaque Eccentricity on Biodegradable Polylactic Acid Stent Implantantion in Stenotic Vessels

Objective To study the effect of plaque eccentricity on stent performance and stress distributions of artery and plaque during stent implantation in stenotic vessels. Methods The stent and idealized stenotic vessels were constructed, and 4 different eccentricities (0%, 20%, 40%, 60%) were attributed to the plaque. Then the stent recoil, stent foreshortening, and stress distributions of artery and plaque when the stent was expanded to the target displacement were analyzed by the finite element method. Results Along with the increase of plaque eccentricity, both stent recoil and stent foreshortening gradually grew. At the same time, the stress of artery and plaque also showed an increasing tread, and high-stress areas gradually approached the narrow side. The maximum von Mises stress of the plaque was much greater than that of the artery. Conclusions Plaque eccentricity had a certain effect on performance of the stent and stress distributions of stenotic vessels. In stent design, the geometry of the plaque should be considered to improve clinical effect of the stent in interventional treatment.