Cerebral Neuromonitoring during Carotid Endarterectomy and Impact of Contralateral Internal Carotid Occlusion

Abstract

The aim of this study was to identify the reliability of carotid artery stump pressure (SP) in predicting the neurologic changes and correlation with contralateral internal carotid artery (ICA) occlusion in patients undergoing eversion carotid endarterectomy (CEA). The optimal method for monitoring cerebral perfusion during CEA, performed under either local or general anesthesia, is still controversial. We prospectively analyzed 118 consecutive patients undergoing eversion CEA under local anesthesia. We had 78 symptomatic (66%) and 40 asymptomatic patients (33.9%). Selective shunting was performed in patients who developed neurologic changes after carotid clamping regardless of SP. Correlation of preoperative symptom status, a degree of stenosis, status of contralateral ICA, arterial blood pressure, SP value, and the intraoperative need for shunting due to neurologic changes was evaluated for both groups: shunted and nonshunted. Selective shunting was performed in 12 patients (10%). There was no significant difference among the groups regarding the demographic characteristics. Mean carotid clamping time was 14.57 minutes. We had no perioperative mortality, stroke, or myocardial infarction. None of the patients required conversion to general anesthesia. We found a mean SP of 31 mm Hg as a reliable threshold for shunting (P < .001; sensitivity 92.3%; specificity 91.3%). Contralateral carotid occlusion was correlated with the significantly lower SP (27 ± 13 mm Hg; P = .001) and the higher need for shunt (50%). SP measurement is a reliable and simple method for monitoring the collateral cerebral perfusion and can predict the need for shunting during CEA. Patients with the contralateral ICA occlusion showed significantly lower SP, although it did not have impact on the outcome.