Faik Isam, Mongrain Rosaire, Leask Richard L, Rodes-Cabau Josep, Larose Eric, Bertrand Olivier
Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada.
Biomed Mater. 2007 Mar;2(1):S28-37. doi: 10.1088/1748-6041/2/1/S05. Epub 2007 Mar 2.
Stenting is becoming the major interventional cardiology procedure worldwide. However restenosis remains a major limitation to the effectiveness of stents. Alterations to the local hemodynamics in the stented segment of the artery could be a potential factor in the development of in-stent restenosis. The characterization of wall shear stress and of blood flow patterns in a stented artery is therefore necessary for a good understanding of the role of hemodynamics in the development of in-stent restenosis. We have used a time-dependent 3D numerical model of a stented coronary artery to study the characteristics of the blood flow and the shear stress distribution. Our results show that the presence of the stent produces significant secondary flow that is limited to an annulus in the near wall region. Low shear stress zones were localized in the vicinity of the struts while the tips of the struts exhibited high values of shear stress. These results support the hypothesis that local hemodynamics may affect the development of in-stent restenosis and could influence the choice of stent geometries for future stent designs.
支架置入术正成为全球主要的介入心脏病学手术。然而，再狭窄仍然是限制支架有效性的主要因素。动脉支架置入段局部血流动力学的改变可能是支架内再狭窄发生的一个潜在因素。因此，为了充分理解血流动力学在支架内再狭窄发生中的作用，有必要对置入支架的动脉中的壁面剪应力和血流模式进行表征。我们使用了一个随时间变化的冠状动脉支架三维数值模型来研究血流特征和剪应力分布。我们的结果表明，支架的存在会产生显著的二次流，且仅限于近壁区域的一个环形区域。低剪应力区位于支柱附近，而支柱尖端则表现出高剪应力值。这些结果支持了这样一种假设，即局部血流动力学可能影响支架内再狭窄的发生，并可能影响未来支架设计中支架几何形状的选择。
