Hemodynamics of the string phenomenon in the internal thoracic artery grafted to the left anterior descending artery with moderate stenosis
Hemodynamics of the string phenomenon in the internal thoracic artery grafted to the left anterior descending artery with moderate stenosis
复制标题
中度狭窄左前降支移植胸廓内动脉串丝现象的血流动力学
DOI：
10.1016/j.jbiomech.2015.11.044
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发表时间：
2016-05-03
影响因子：
2.4
通讯作者：
Zhao, Zhou
中科院分区：
文献类型：
--
作者：
Zhao, Xi;Liu, Youjun;Zhao, Zhou
目的：胸廓内动脉具有良好的长期通畅性，是冠状动脉旁路移植术的首选血管。然而，胸廓内动脉移植失败仍然发生由于弥漫性狭窄，被称为弦现象。研究认为，在冠状动脉狭窄不严重时，弦线现象是由竞争性血流引起的，但弦线现象的血流动力学机制尚不清楚。本研究的目的是阐明弦现象的血流动力学特征。材料：建立了患者特定的主动脉弓和冠状动脉的三维模型。左前降支动脉中度狭窄。使用胸廓内动脉绕过狭窄。方法：将3D动脉模型与心血管系统的0维集中参数模型耦合，进行数值模拟研究，结果：计算得到了移植物流量、冠状动脉流量、壁面切应力和振荡剪切指数，并给出了数值结果。结论：高振荡剪切指数可能是胸廓内动脉桥血管弦线现象的主要血流动力学特征。反向移植物血流和夹闭狭窄引起的移植物血流差异可用于评估观察到串现象的概率。(C)2015爱思唯尔有限公司版权所有。
Purpose: The internal thoracic artery is the choice of graft for coronary artery bypass grafting due to the excellent long-term patency. However internal thoracic artery graft failures still occur due to diffuse narrowing, known as the string phenomenon. Studies suggest that the string phenomenon is caused by competitive flow when the coronary stenosis is not serious, but the hemodynamics of the string phenomenon are still unclear. The purpose of this study is to clarify the hemodynamic characteristics of the string phenomenon.Materials: A patient-specific 3-dimensional model of the aortic arch and coronary arteries was reconstructed. A moderate stenosis was applied to the left anterior descending artery. The internal thoracic artery was used to bypass the stenosis. Two further 3D models were built to study the hemodynamics of the string phenomenon.Methods: A numerical study was performed by coupling the 3D artery model with 0-dimensional lumped parameter model of the cardiovascular system.Results: The graft flow, native coronary flow, wall shear stress and oscillatory shear index were calculated and illustrated. Inverse flow and high oscillatory shear index appeared on the internal thoracic artery graft when the stenosis was moderate.Conclusion: High oscillatory shear index might be the major hemodynamic characteristic of the string phenomenon in internal thoracic artery graft. The inverse graft flow and,the difference in graft flow caused by clamping the stenosis can be used to evaluate the probability of observing the string phenomenon. (C) 2015 Elsevier Ltd. All rights reserved.