Samijo S K, Barkhuysen R, Willigers J M, Leunissen K M L, Ledoux L A F, Kitslaar P J E H M, Hoeks A P G
Department of Biophysics, Cardiovascular Research Institute, Maastricht, The Netherlands.
Nephron. 2002;92(3):557-63. doi: 10.1159/000064085.
Under physiological circumstances in the common carotid artery (CCA), mean wall shear stress (WSS), defined as mean wall shear rate (WSR) times local whole blood viscosity (WBV), is maintained at approximately 1.5 Pa. In patients with end-stage renal failure (ESRF) whole blood viscosity is low and it is not unlikely that mean WSS is lower in these patients than in control subjects. Moreover, hemodialysis causes an acute increase in blood viscosity with possible effects on WSS. In this study WSS in the CCA was determined with the Shear Rate Estimating System, an apparatus based on ultrasound, in ESRF patients (n = 13) and in presumed healthy age- and sex-matched control subjects (n = 13). Prior to hemodialysis, mean WSS (0.67 +/- 0.23 Pa) was significantly lower (p < 0.05) in patients with ESRF, due to both a lower WBV (2.80 +/- 0.52 mPa.s) and mean WSR (271 +/- 109 s(-1)), than in the control subjects (mean WSS: 1.24 +/- 0.20 Pa; WBV: 3.20 +/- 0.29 mPa.s; WSR: 387 +/- 51 s(-1)). Hemodialysis induced an increase in WBV (up to 3.71 +/- 1.54 mPa.s, p < 0.01), but mean WSS did not change significantly due to a reciprocal decrease in mean wall shear rate. These findings demonstrate that WSS is lower in hemodialysis patients than in control subjects, and that mean WSS is maintained at this low level despite an acute change in blood viscosity.
在生理情况下，颈总动脉（CCA）的平均壁面切应力（WSS）定义为平均壁面切变率（WSR）乘以局部全血粘度（WBV），维持在约1.5 Pa。在终末期肾衰竭（ESRF）患者中，全血粘度较低，这些患者的平均WSS很可能低于对照组。此外，血液透析会导致血液粘度急性升高，可能会对WSS产生影响。在本研究中，使用基于超声的切变率估计系统测定了ESRF患者（n = 13）和假定健康的年龄及性别匹配的对照组（n = 13）的CCA中的WSS。血液透析前，ESRF患者的平均WSS（0.67 +/- 0.23 Pa）显著低于对照组（p < 0.05），这是由于较低的WBV（2.80 +/- 0.52 mPa·s）和平均WSR（271 +/- 109 s⁻¹）所致，而对照组的平均WSS为1.24 +/- 0.20 Pa；WBV为3.20 +/- 0.29 mPa·s；WSR为387 +/- 51 s⁻¹。血液透析导致WBV升高（高达3.71 +/- 1.54 mPa·s，p < 0.01），但由于平均壁面切变率的相应降低，平均WSS没有显著变化。这些发现表明，血液透析患者的WSS低于对照组，并且尽管血液粘度发生急性变化，平均WSS仍维持在较低水平。
