Carotid endarterectomies: who are the candidates at risk?

Abstract Of Reviewed Article: Predictors of clamp-induced electroencephalographic changes during carotid endarterectomies.Simon MV, Chiappa KH, Kilbride RD, Rordorf GA, Cambria RP, et al.J Clin Neurophysiol 2012t;29:462-467.

Objective: Electroencephalograms detect clamp-induced cerebral ischemia during carotid endarterectomy, and thus impact management and minimize the risk of perioperative stroke. We hypothesized that age, preoperative neurologic symptoms, ≥70% contralateral carotid, and bilateral vertebral stenosis increase the probability of clamp-induced electroencephalogram changes, whereas ≥70% unilateral carotid stenosis does not.

Methods: This is an observational cohort study of 299 patients who underwent carotid endarterectomy with electroencephalogram monitoring at a single large urban academic medical center in 2009. Univariate and multivariate logistic regression analyses were used.

Results: Seventy percent or greater ipsilateral carotid stenosis decreases the odds of clamp-induced neurophysiologic dysfunction (odds ratio = 0.43, 95% confidence interval [0.18-0.99], P = 0.04) after adjustment for symptomatic status, degree contralateral carotid or vertebral stenosis, and age. Preoperative neurologic symptoms, ≥70% contralateral carotid stenosis, and bilateral extracranial vertebral stenosis independently increase these odds (odds ratio 2.62, 95% confidence interval [1.32-5.18], P = 0.005; odds ratio 2.84, 95% confidence interval [1.27-6.34], P = 0.01; and odds ratio 3.58, 95% confidence interval [1.02-12.53], P = 0.04, respectively), after adjustment for the other factors. Age ≥70 years has no significant impact.

Conclusions: Preoperative neurologic symptoms, ≥70% contralateral carotid, and bilateral vertebral stenosis increase the probability of clamp-induced ischemia as detected by intraoperative electroencephalogram, whereas ≥70% ipsilateral carotid stenosis decreases it.