Cerebral perfusion affects the risk of ischemia during carotid artery stenting

Patients with impaired perfusion in the hemisphere ipsilateral to a stenotic internal carotid artery may have a higher risk of cerebral ischemic complications than those with normal perfusion. We therefore studied whether the occurrence of new ischemic lesions after carotid artery stenting is related to cerebral perfusion.

In 45 patients with symptomatic carotid artery stenosis, CT perfusion and magnetic resonance diffusion-weighted imaging (DWI) were performed before carotid artery stenting; DWI was repeated within 2 days thereafter. Cerebral blood volume (CBV), mean transit time (MTT), and cerebral blood flow (CBF) were measured with CT perfusion in the cortical flow territory of the middle cerebral artery. Hyperintense lesions on postprocedural DWI not visible on baseline DWI were considered new cerebral ischemic lesions. The relation between CBF, CBV, and MTT and new ipsilateral ischemic lesions was tested with logistic regression.

In 11 of the 45 (24%) patients, new ischemic lesions were found in the ipsilateral hemisphere. The occurrence of these lesions was related to a lower CBF [adjusted odds ratio (aOR), 0.96; 95% confidence interval (CI), 0.92-1.00] and a longer MTT (aOR, 1.65; 95% CI, 1.02-2.66) compared with ipsilateral hemispheres without new lesions.

Patients with impaired cerebral perfusion are more prone to develop ischemic lesions during carotid artery stenting. This suggests that in ischemic stroke during or after carotid artery stenting, embolic and hemodynamic mechanisms act in concert.