The distribution and size of ischemic lesions after carotid artery angioplasty and stenting: Evidence for microembolization to terminal arteries

BackgroundMuch of the brain is perfused by penetrating arteries that are the “single source” of blood to their surrounding tissues. These tissues should be equally vulnerable to ischemia from embolic occlusion, but there are questions about whether emboli have access to the penetrating arteries serving the deep brain tissues. To examine this issue in humans we recorded the number and distribution of new ischemic lesions on diffusion-weighted magnetic resonance imaging (DWMRI) after carotid artery stenting (CAS), a procedure producing showers of numerous small atheroemboli.MethodsTwenty-nine men (aged 62-81) underwent 30 CAS procedures with distal protection in place, and DWMRI 48 hours after the procedure documented new lesions had developed. Thirteen patients were asymptomatic, and 16 had experienced recent symptoms ipsilateral to the treated carotid stenosis. A DWMRI study was done in each patient ≤72 hours before the procedure. All MRI studies were read by the same neuroradiologist.ResultsOne patient sustained a minor stroke, which resolved. DWNRI found 131 new lesions (median, 3; range, 1-17; interquartile range, 2-4). Lesion size was