Adaptive common carotid arteries remodeling after unilateral internal carotid artery occlusion in adult patients

Objective: This study was undertaken in human adults to examine modificatio ns in common carotid internal diameter (ID), intima-media thickness (IMT), cross-sectional area (CSA) and wall shear stress (WSS) occurring both on th e ipsilateral side of an internal carotid artery (ICA) occlusion and on the non-occluded contralateral side. Methods: Seventeen patients with unilater al ICA occlusion had repeated echo-Doppler examinations during 1 year and w ere compared to 12 volunteers with control non-occluded common carotid arte ries (CCA). Results: The cause of ICA occlusion was atherosclerosis in nine patients, dissection in five, and undetermined in three. The results showe d a significant reduction in ID on the occluded side (5.15+/-0.30 mm) compa red with the non-occluded side (5.96+/-0.20 mm, P<0.05) and with control ar teries (5.55+/-0.10, P<0.05). A significant reduction in blood flow was obs erved on the occluded side (404+/-58 ml/min) compared with the non-occluded side (703+/-'51 ml/min, P<0.0001) and with controls (567+/-27 ml/min, P<0. 0001). Wall cross-sectional area was found to be positively correlated to b lood flow (r=0.35, P<0.01), without any significant difference in mean CSA between both sides. Interestingly, wall shear stress values were identical on both sides whatever the cause of ICA occlusion, and did not differ from those in controls. Conclusions: Our results suggest that in humans, the int ernal diameter of the common carotid artery decreases in response to chroni c decrease in blood flow, in order to maintain a constant wall shear stress even in pathological arteries. (C) 2001 Elsevier Science B.V. All rights r eserved.