BLOOD VELOCITY PROFILES IN THE ORIGIN OF THE CANINE RENAL-ARTERY AND THEIR RELEVANCE IN THE LOCALIZATION AND DEVELOPMENT OF ATHEROSCLEROSIS
BLOOD VELOCITY PROFILES IN THE ORIGIN OF THE CANINE RENAL-ARTERY AND THEIR RELEVANCE IN THE LOCALIZATION AND DEVELOPMENT OF ATHEROSCLEROSIS
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DOI：
10.1161/01.atv.12.5.626
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发表时间：
1992-05-01
期刊：
影响因子：
--
通讯作者：
KAJIYA, F
中科院分区：
文献类型：
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作者：
YAMAMOTO, T;TANAKA, H;KAJIYA, F
我们使用 20 MHz 80 通道脉冲多普勒测速仪和 30 MHz 高分辨率回波超声，通过测量 10 只麻醉犬手术暴露的左肾动脉的速度分布和分叉几何形状，研究了肾动脉起源处的体内血流动力学。主动脉与肾动脉之间的夹角范围为60度至90度（平均84度），尽管分叉点并不位于单一的前背平面，并且肾动脉直径范围为1.5至3.5毫米（平均2.4毫米）。尽管几何形状不同，但不同主动脉肾分叉处的速度分布相似。尽管观察到反向速度区域，但在整个心动周期中肾动脉中的净流量是向前的。峰值雷诺数为 486 +/- 63。平行于分叉的平面中近端肾动脉的速度分布显示在整个心动周期中速度矢量指向尾壁。即使在心脏收缩期间，在颅壁附近也可以观察到表明分离情况的逆流。当探头垂直于颅壁放置时，观察到从颅侧到尾侧的速度分量。在距肾口四个直径的距离处，速度分布几乎呈抛物线形。这些结果表明，容易发生动脉粥样硬化病变的肾口颅壁附近的速度模式具有以下特征：1）低时均剪切率，2）血流分离，3）血流随时间变化的振荡。
Using a 20-MHz 80-channel pulsed Doppler velocimeter and 30-MHz high-resolution echo ultrasound, we investigated the in vivo hemodynamics at the origin of the renal artery by measuring the velocity profiles and bifurcation geometry of a surgically exposed left renal artery in 10 anesthetized dogs. The angle between the aorta and the renal artery ranged from 60-degrees to 90-degrees (mean, 84-degrees) although the bifurcation did not lie in a single anterodorsal plane and the diameter of the renal artery ranged from 1.5 to 3.5 mm (mean, 2.4 mm). Despite different geometries, the velocity profiles in the different aortorenal bifurcations were similar. Although regions of reverse velocity were observed, the net flow in the renal artery was in the forward direction throughout the cardiac cycle. The peak Reynolds' number was 486 +/- 63. The velocity profiles in the proximal renal artery in the plane parallel to the bifurcation showed velocity vectors directed toward the caudal wall throughout the cardiac cycle. Reverse flow, indicating How separation, was observed near the cranial wall even during systole. When the probe was placed on the cranial wall perpendicular to the wall, a velocity component from the cranial side to the caudal side was observed. At a distance of four diameters from the renal ostia, velocity profiles were almost parabolic. These results indicate that the velocity pattern near the cranial wall at the renal ostia, at which atherosclerotic lesions are prone to develop, are characterized by 1) a low time-averaged shear rate, 2) separation of the flow, and 3) a time-varying oscillation of the flow.