Objectives: To characterise changes in blood flow in the major cerebral arteries before and after carotid endarterectomy (CEA).
Design: Prospective, non-randomised, observational study.
Materials: Twenty-nine patients with symptomatic, unilateral, severe stenosis of the internal carotid artery (ICA) undergoing CEA and 16 control subjects.
Methods: Quantitative blood flow volume measurement using magnetic resonance angiography (MRA) on both symptomatic and asymptomatic sides in the common carotid artery (CCA), ICA, and middle cerebral artery (MCA) and in the basilar artery, 1 week before and 3 months after CEA.
Results: Before CEA, blood flow was decreased on the symptomatic side in the CCA, ICA, and MCA as compared to the contralateral side and to control subjects (p < 0.001). After CEA, flow on the symptomatic side in the CCA, ICA, and MJCA was increased to normal level (p < 0.005) and flow in the basilar artery was decreased to normal level (p < 0.005).
Conclusions: These results demonstrate that arterial blood flow to the symptomatic hemisphere is decreased in patients with severe ICA stenosis. CEA restores arterial blood flow, rendering cerebral blood flow less dependent on collateral flow through the basilar artery. MRA flow measurements provide new insight in the complex haemodynamics of the extra- and intracranial circulation.