Basal Ganglia's influence on awake test in carotid endarterectomy

Abstract

Background: White matter changes (WMC) have been associated with the underlying presence of chronic cerebral ischemia, such as in carotid stenosis and age-related white matter changes (ARWMC). A low attenuation on computed tomography (CT) characterizes these alterations. Patients undergoing carotid endarterectomy (CEA) with severe WMC may be at increased risk of intraoperative neurologic deficits (IND) during carotid clamping. This study aims to determine the potential role of ARWMC as a predictor of IND during CEA with regional anesthesia (RA).

Methods: Patients undergoing CEA under RA at a tertiary referral center, who presented with IND during CEA were prospectively and consecutively recruited between January 2011 and December 2023. The control group comprised the immediately consecutive patient who underwent the same procedure without IND. From this sample, patients with preoperative CT were selected and compared based on ARWMC score (≤ 1 and 2). Differences in demographics and comorbidities were assessed between the groups. A multivariable logistic regression was performed.

Results: One hundred and twenty-one patients were enrolled. Patients with IND had a significantly higher ARWMC score in basal ganglia (ARWMC-BG ≥ 2) and posterior circulation disease was more frequent (27.8 %). No significant differences were observed in anatomical variations of the circle of Willis. For patients with ARWMC-BG ≥ 2, a significant burden of other comorbidities was associated, such as chronic kidney disease, coronary disease, and atrial fibrillation. After multivariable logistic regression analysis, ARWMC-BG score ≥ 2 was an independent risk factor for IND (aOR 3.472).

Conclusion: An ARWMC-BG score above 2 predicts positive intraoperative "awake tests" in CEA with RA, constituting a reliable tool to stratify patients according to their risk of adverse events. However, larger prospective cohorts are needed to validate these findings and offer a better selection and management of this subset of patients.

Keywords: Brain ischemia; Carotid stenosis; Leukoaraiosis; Regional anesthesia.