Determination of in vivo velocity and endothelial shear stress patterns with phasic flow in human coronary arteries: A methodology to predict progression of coronary atherosclerosis
Determination of in vivo velocity and endothelial shear stress patterns with phasic flow in human coronary arteries: A methodology to predict progression of coronary atherosclerosis
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DOI：
10.1067/mhj.2002.123118
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发表时间：
2002-06-01
影响因子：
4.8
通讯作者：
Stone, PH
中科院分区：
文献类型：
--
作者：
Feldman, CL;Ilegbusi, OJ;Stone, PH
背景：虽然冠状动脉同样暴露于系统性危险因素，但冠状动脉粥样硬化是局灶性的和偏心性的，并且每个病变都以独立的方式发展。剪切力的变化在内皮细胞中引起明显不同的体液、代谢和结构反应，低剪应力区域促进动脉粥样硬化，而高剪应力区域防止动脉粥样硬化。在活体内研究影响冠状动脉的剪应力特征可能有助于预测冠状动脉疾病的进展，预测哪些斑块可能破裂，以及预测经皮冠状动脉介入治疗后再狭窄的部位。方法采用冠状动脉内超声和双平面冠状动脉造影术相结合的方法，在定向动脉粥样硬化术后立即测定右冠状动脉一段的三向解剖结构，以确定内皮剪应力。管段的几何形状用曲线坐标表示，并用计算流体力学技术研究了详细的相速度分布和剪应力分布。结果我们的方法确定了动脉内轻微的血流逆转、显著的漩涡以及局部速度和剪应力的大变化--时间、轴向和周向--即使在没有明显的管腔阻塞的情况下。结论我们首次描述了一种能够在体内测定人冠状动脉局部脉动速度模式和内皮剪应力的系统。血流现象表现出与动脉粥样硬化和再狭窄的局灶性特征相一致的特征。
Background Although the coronary arteries are equally exposed to systemic risk factors, coronary atherosclerosis is focal and eccentric, and each lesion evolves in an independent manner. Variations in shear stress elicit markedly different humoral, metabolic, and structural responses in endothelial cells, Areas of low shear stress promote atherosclerosis, whereas areas of high shear stress prevent atherosclerosis. Characterization of the shear stresses affecting coronary arteries in humans in vivo may permit prediction of progression of coronary disease, prediction of which plaques might become vulnerable to rupture, and prediction of sites of restenosis after percutaneous coronary intervention.Methods To determine endothelial shear stress, the 3-climensional anatomy of a segment of the right coronary artery was determined immediately after directional atherectomy by use of a combination of intracoronary ultrasound and biplane coronary angiography. The geometry of the segment was represented in curvilinear coordinates and a computational fluid dynamics technique was used to investigate the detailed phasic velocity profile and shear stress distribution. The results were analyzed with several conventional indicators and one novel indicator of disturbed flow.Results Our methodology identified areas of minor flow reversals, significant swirling, and large variations of local velocity and shear stress -temporally, axially, and cirumferentially-within the artery, even in the absence of significant luminal obstruction.Conclusions We have described a system that permits, for the first time, the in vivo determination of pulsatile local velocity patterns and endothelial shear stress in the human coronary arteries. The flow phenomena exhibit characteristics consistent with the focal nature of atherogenesis and restenosis.