PULSATILE FLOW VISUALIZATION IN THE ABDOMINAL-AORTA UNDER DIFFERING PHYSIOLOGICAL CONDITIONS - IMPLICATIONS FOR INCREASED SUSCEPTIBILITY TO ATHEROSCLEROSIS
PULSATILE FLOW VISUALIZATION IN THE ABDOMINAL-AORTA UNDER DIFFERING PHYSIOLOGICAL CONDITIONS - IMPLICATIONS FOR INCREASED SUSCEPTIBILITY TO ATHEROSCLEROSIS
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DOI：
10.1115/1.2891400
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发表时间：
1992-08-01
影响因子：
1.7
通讯作者：
GLAGOV, S
中科院分区：
文献类型：
--
作者：
MOORE, JE;KU, DN;GLAGOV, S
肾下腹主动脉是临床上严重动脉粥样硬化的常见部位。正如其他易感部位所示，血管几何形状、分流率和脉动性可能导致影响腹主动脉段疾病优先定位的血流动力学状况。脉动流可视化是在血管造影片和尸体动脉测量构建的主动脉玻璃模型中进行的。改变流速和脉动波形以反映典型的生理条件。在正常静息状态下，肾下主动脉的血流模式比肾上主动脉的血流模式复杂。随时间变化的旋涡图案出现在肾动脉的水平，并通过肾下主动脉传播到髂总动脉。从肾动脉到主动脉分叉处沿着后壁有一个振荡速度方向的区域。染料被沿着后壁截留，需要几个心动周期清除。相比之下，前主动脉中的染料快速清除。在餐后条件下，主动脉的血流模式基本不变。模拟运动条件下产生的层流血流动力学特征与静息条件下非常不同，包括染料停留时间的减少。这项研究揭示了显着的时间依赖性变化的腹主动脉血流动力学在不同的生理条件下。血流动力学因素，如低壁剪切应力，振荡剪切方向，和高颗粒停留时间可能与临床上看到的优先斑块定位在肾下主动脉。
The infrarenal abdominal aorta is a common site for clinically significant atherosclerosis. As has been shown in other susceptible locations, vessel geometry, flow division rates, and pulsatility may result in hemodynamic conditions which influence the preferential localization of disease in the abdominal aorta segment. Pulsatile flow visualization was performed in a glass model of the aorta constructed from measurements of angiograms and cadaver aortas. Flow rates and pulsatile waveforms were varied to reflect typical physiological conditions. Under normal resting conditions, the flow patterns in the infrarenal aorta were more complex than those in the suprarenal location. Time varying vortex patterns appeared at the level of the renal arteries and propagated through the infrarenal aorta into the common iliac arteries. A region of oscillating velocity direction extended from the renal arteries to the aortic bifurcation along the posterior wall. Dye became trapped along the posterior wall requiring several cardiac cycles for clearance. In contrast, there was rapid clearance of the dye in the anterior aorta. Under postprandial conditions, the flow patterns in the aorta were basically unchanged. Simulated exercise conditions created laminar hemodynamic features very different from the resting conditions, including a decrease in dye residence time. This study reveals significant time-dependent variations in the hemodynamics of the abdominal aorta under differing physiologic conditions. Hemodynamic factors such as low wall shear stress, oscillating shear direction, and high particle residence time may be related to the clinically seen preferential plaque localization in the infrarenal aorta.