中文摘要：

目的研究冠脉内植入药物释放支架后的血液流动特性，为临床应用及改善药物洗脱支架的设计提供理论指导。方法建立病灶部位植入药物洗脱支架后的数值模型，利用计算流体动力学方法进行药物浓度分布及壁面剪切力分布的数值分析研究，并将计算结果与裸金属支架植入后的计算结果进行比较。结果药物洗脱支架在血流过程中产生的低壁面剪切力区域几乎都伴随着较高的药物浓度分布，而低药物浓度区域则伴随的是较高的壁面剪切力分布，显著地减少了低壁面剪切力区域或低药物浓度区域独立存在的区域。理论上，药物释放支架在药物释放阶段比植入裸金属支架具有优越性。结论药物洗脱支架能够显著降低支架内的再狭窄率。详细了解药物洗脱支架的流场分布规律将有利于改善药物洗脱支架的设计，进一步提高支架的整体性能，为临床应用提供理论依据。

英文摘要：

Objective To study the hemodynamic characteristics after vascular drug-eluting stent （DES） implanta- tion, so as to provide theoretical guidance for clinical application of DES as well as improving the design of DES. Methods The geometry models of vascular lesions implanted with DES were constructed to numerically analyze drug concentration and wall shear stress （WSS） distributions in vessel by computational fluid dynamics （CFD） method. The results were compared with flow characteristics of the model with bare metal stent （BMS） implanta- tion. Results Low WSS accompanied by high drug concentration would occur during blood flow in some areas af- ter DES implantation, and vice versa. The presence of DES significantly reduced appearing such areas as either with low WSS only or with low drug concentration only. Theoretically, DES had more advantages than BMS at the stage of drug release. Conclusions DES could dramatically reduce the ratio of in-stent restenosis. Understanding the regular pattern of blood flow field distributions after DES implantation in detail will be beneficial to improve the design of DES, and further advance the overall performance of the stent, which can provide the theoretical basis for clinical research.