Kornet L, Hoeks A P, Lambregts J, Reneman R S
Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
J Vasc Res. 2000 Mar-Apr;37(2):112-22. doi: 10.1159/000025722.
In elastic arteries, mean wall shear stress appears to be close to 1. 5 Pa, the value predicted by the theory of minimal energy loss. This finding in elastic arteries does not necessarily represent the situation in muscular arteries. Elastic arteries have to store potential energy, while muscular arteries have mainly a conductive function. Therefore, we determined wall shear stress and its age dependency in the common and superficial femoral arteries, 2-3 cm from the flow divider in 54 presumed healthy volunteers between 21 and 74 years of age, using a non-invasive ultrasound system. Prior to the study, the reliability of this system was determined in terms of intrasubject variation. Mean wall shear stress was significantly lower in the common femoral artery (0.35 +/- 0.18 Pa) than in the superficial femoral artery (0.49 +/- 0.15 Pa). In all age categories, peak systolic wall shear stress and the maximal cyclic change in wall shear stress were not significantly different in the common and the superficial femoral arteries. Peak systolic wall shear stress in the common and the superficial femoral arteries was not significantly different from the value previously determined in the common carotid artery, but mean wall shear stress was lower in the common and superficial femoral arteries than in the common carotid artery by a factor of 2-4. In both the common and the superficial femoral arteries, mean, peak systolic and maximal cyclic change in wall shear stress did not change significantly with age, nor did diameter. We conclude that, as compared to elastic arteries, mean wall shear stress is low in the conductive arteries of a resting leg, due to backflow during the first part of the diastolic phase of the cardiac cycle and the absence of flow during the rest of the diastolic phase. Mean wall shear stress is lower in the common than in the superficial femoral artery due to additional reflections from the deep femoral artery.
在弹性动脉中，平均壁面剪应力似乎接近1.5帕，这是最小能量损失理论预测的值。弹性动脉中的这一发现不一定代表肌性动脉的情况。弹性动脉必须储存势能，而肌性动脉主要具有传导功能。因此，我们使用非侵入性超声系统，在54名年龄在21至74岁之间的假定健康志愿者中，测定了股总动脉和股浅动脉距血流分支2 - 3厘米处的壁面剪应力及其年龄依赖性。在研究之前，根据受试者内变异确定了该系统的可靠性。股总动脉的平均壁面剪应力（0.35±0.18帕）显著低于股浅动脉（0.49±0.15帕）。在所有年龄组中，股总动脉和股浅动脉的收缩期峰值壁面剪应力以及壁面剪应力的最大周期性变化均无显著差异。股总动脉和股浅动脉的收缩期峰值壁面剪应力与先前在颈总动脉中测定的值无显著差异，但股总动脉和股浅动脉的平均壁面剪应力比颈总动脉低2 - 4倍。在股总动脉和股浅动脉中，壁面剪应力的平均值、收缩期峰值和最大周期性变化均不会随年龄显著变化，直径也不会。我们得出结论，与弹性动脉相比，静息腿部的传导性动脉中的平均壁面剪应力较低，这是由于心动周期舒张期第一部分存在逆流以及舒张期其余时间无血流。由于来自股深动脉的额外反射，股总动脉中的平均壁面剪应力低于股浅动脉。
