Wall shear stress assessment in the common carotid artery of end-stage renal failure patients

Area of Science:

• Cardiovascular Physiology
• Nephrology
• Biomedical Engineering

Background:

• Mean wall shear stress (WSS) in the common carotid artery (CCA) is physiologically maintained around 1.5 Pa.
• Patients with end-stage renal failure (ESRF) exhibit lower whole blood viscosity (WBV), potentially leading to reduced mean WSS.
• Hemodialysis can acutely increase blood viscosity, impacting WSS.

Purpose of the Study:

• To investigate and compare mean WSS in the CCA of ESRF patients and healthy controls.
• To assess the effect of hemodialysis on WSS in ESRF patients.

Main Methods:

• Utilized the Shear Rate Estimating System, an ultrasound-based apparatus, to measure WSS.
• Studied 13 ESRF patients and 13 age- and sex-matched healthy control subjects.
• Measured WSS, WBV, and mean wall shear rate (WSR) before and after hemodialysis in ESRF patients.

Main Results:

• Pre-hemodialysis, ESRF patients showed significantly lower mean WSS (0.67 ± 0.23 Pa) compared to controls (1.24 ± 0.20 Pa).
• This reduction in ESRF patients was attributed to lower WBV (2.80 ± 0.52 mPa.s vs. 3.20 ± 0.29 mPa.s) and WSR (271 ± 109 s⁻¹ vs. 387 ± 51 s⁻¹).
• Hemodialysis increased WBV (up to 3.71 ± 1.54 mPa.s) but did not significantly alter mean WSS due to a reciprocal decrease in WSR.

Conclusions:

• Mean WSS in the CCA is significantly lower in hemodialysis patients compared to healthy individuals.
• Despite acute changes in blood viscosity during hemodialysis, mean WSS remains relatively stable at a lower level in ESRF patients.
• Findings highlight altered hemodynamics in ESRF patients and the body's compensatory mechanisms during hemodialysis.