Changes in cerebral blood flow after carotid endarterectomy.

We evaluated changes in cerebral blood flow (CBF) after carotid endarterectomy (CEA) in patients with internal carotid (ICA) stenosis. We studied 46 patients with ICA stenosis who underwent CEA. The mean age of the patients was 63 years, and their mean ICA stenosis was 73%. CBF in the middle cerebral artery territory was measured with xenon-enhanced CT tomography (Xe-CT) before and 3 weeks after CEA. In addition, cerebrovascular reactivity (CVR) was measured after intravenous administration of acetazolamide (ACZ) in 16 patients. There was no significant relationship between the degree of stenosis and CBF. Ten patients had decreased CBF before CEA, and CBF improved in nine of these after CEA. The CVR in 6 of 7 patients with impaired CVR before CEA improved to varying degrees after CEA. The CBF in patients with ICA stenosis varied according to the degree of collateral circulation. In conclusion, CEA can increase CBF and improve CVR in patients with low CBF or low CVR by restoring blood flow through the ICA.