In the femoral artery bifurcation, differences in mean wall shear stress within subjects are associated with different intima-media thicknesses

In elastic arteries, intima-media thickening is more pronounced in areas wi th low than with high mean and peak wall shear stress. These findings in el astic arteries are not necessarily representative of the situation in muscu lar arteries. The former arteries have to store volume energy, whereas the latter are mainly conductive vessels. It was the aim of the present study t o investigate noninvasively whether differences in wall shear stress within a muscular artery bifurcation, if any, were associated with different inti ma-media thicknesses (IMTs). The effect of age on the possible differences was assessed as well. We determined IMT and mean, peak systolic, and the ma ximum cyclic change in shear stress near the posterior wall in the common ( FC) and the superficial (FS) femoral artery 20 to 30 mm from the flow divid er in 54 presumed healthy subjects between 21 and 74 years of age. Results were considered in terms of intrasubject differences. Before the study, the reliability of the ultrasonic system to assess wall sheer rate and IMT was determined in terms of intrasubject variability. IMT at the posterior wall was significantly larger in the FC than in the FS, probably owing to the s ignificantly lower mean wall shear stress at this site in the FC. The relat ive differences in IMT and mean wall shear stress between FC and FS were in dependent of age. The difference in wall shear stress between both arteries can likely be explained by a different influence of reflections. In both t he FC and FS, mean, peak systolic, and maximum cyclic change in shear stres s near the posterior wall did not change significantly with age, whereas IM T did increase significantly with age.