Subclinical Cerebral Embolization During Carotid Revascularization

This complication might cause subtle cognitive impairment.

We know that subclinical cerebral embolization (detected by transcranial Doppler ultrasound or diffusion-weighted magnetic resonance imaging [MRI]) occurs during carotid artery revascularization — more so with stenting than with endarterectomy. Two studies shed additional light on this complication.

In a University of Texas study, 40 patients with carotid stenosis underwent stenting; stenoses were symptomatic (i.e., associated with previous stroke or transient ischemic attack [TIA]) in 17 patients and asymptomatic in 23. On transcranial Doppler, microembolic counts during procedures were similar in symptomatic and asymptomatic patients (median, about 300). Diffusion-weighted MRI, done immediately before and 24 hours after stenting, demonstrated new acute cerebral embolic lesions in half of both symptomatic and asymptomatic patients. However, the lesions were not associated with clinically evident stroke or TIA.

Stanford researchers performed extensive neurocognitive testing 1 week before and 1 month after carotid interventions in 51 patients (endarterectomy, 35; stenting, 16). Postprocedure diffusion-weighted MRI revealed new ipsilateral lesions in 50% of stent patients and in 9% of surgery patients (P=0.02). A postprocedure decline in memory was detected in 50% of stent patients and in 39% of surgery patients. On multivariable analysis, having an abnormality on postprocedure diffusion-weighted MRI was associated with memory decline (P=0.02).

Citation(s):

Tulip HH et al. Cerebral embolization in asymptomatic versus symptomatic patients after carotid stenting. J Vasc Surg 2012 Dec; 56:1579.

Zhou W et al. Prospective neurocognitive evaluation of patients undergoing carotid interventions. J Vasc Surg 2012 Dec; 56:1571.