支架参数对血管壁面剪切应力的影响

目的研究不同支架参数对血管壁面再狭窄的影响,为设计支架形式提供参考和依据。方法根据支柱的螺纹节距、支柱数目、支柱线径、支架突入流域深度、支柱截面形状对支架进行分组,利用三维计算流体动力学(computational fluid dynamics,CFD)模拟方法研究各个参数的不同设置对血管壁面剪切应力分布的影响。结果支架的支柱线径对壁面剪切应力影响最为显著,并且支架参数中节距变短、支柱数目增加、线径变宽、突入流域深度增加会导致壁面低剪切应力区域面积增加;相对于三角形与正方形截面形状,圆形截面支架导致的低剪切应力区域面积更少。结论支架在设计过程中应采用圆形截面,而且应尽可能缩小线径,增长节距,减少支柱数目,减小突入流域深度。

Effects of stent parameters on vascular wall shear stress

Objective To investigate the effects of different stent parameters on the development of restenosis, so as to provide references and basis for the design of stent forms. Methods Stents were categorized into groups according to stent unite length, strut number, strut cross-section diameter, stent depth into fluid, strut cross-section shape. The influence of different parameter settings on wall shear stress distributions was investigated based on three-dimensional computational fluid dynamics (CFD) simulation. Results The strut cross-section diameter had the most obvious impact on wall shear stress. It would lead to the increase of low wall shear stress area with shorter stent unite length, more strut number, larger strut cross-section diameter and deeper stent depth into the fluid. In comparison with triangular and square cross-section shape, the low shear stress area was much smaller by using stent with circular cross-section. Conclusions It is suggested that the circular cross-section shape should be adopted in stent design, with preference to reducing strut cross-section diameter, strut number and stent depth into the fluid, while increasing stent unite length.