Cerebral Microemboli and Brain Injury During Carotid Artery Endarterectomy and Stenting

Background and Purpose— Cerebral microembolic signals detected by transcranial Doppler are frequent during carotid angioplasty with stenting and carotid endarterectomy (CEA). Their potential harmful effects on the brain are, however, unclear. The aim of this study was to relate the frequency and type of per-procedural microembolic signals to procedure-related ipsilateral ischemic strokes and new ipsilateral ischemic lesions on diffusion-weighted cerebral MRI. Methods— Eighty-five patients who were prospectively treated with CEA (61) or carotid angioplasty with stenting (30) for high-grade (≥70%) internal carotid artery stenoses were monitored during the procedures using multifrequency transcranial Doppler with embolus detection and differentiation. Pre- and postprocedural cerebral diffusion-weighted cerebral MRIs were performed on a subset of patients. Results— Solid and gaseous microemboli were independently associated with procedure-related ipsilateral ischemic strokes (solid: P =0.027, gaseous: P =0.037) or new ipsilateral diffusion-weighted cerebral MRI lesions (solid: P =0.043, gaseous: P =0.026). Microembolic signals were detected during all procedures except one (CEA); 17% and 21% of all emboli were solid during carotid angioplasty with stenting and CEA, respectively. Patients undergoing carotid angioplasty with stenting had more solid ( P <0.001) and gaseous ( P <0.001) emboli and more new ipsilateral ischemic strokes ( P =0.033) compared with patients undergoing CEA. Echolucent plaques ( P =0.020) and preprocedural diffusion-weighted cerebral MRI ischemic lesions ( P =0.002) were associated with increased numbers of solid emboli. Conclusions— Solid and gaseous microemboli were increased in patients with procedure-related ipsilateral ischemic strokes or new diffusion-weighted cerebral MRI lesions, which suggests that both solid and gaseous emboli may be harmful to the brain during CEA and carotid angioplasty with stenting.