Diagnostic accuracy of intraoperative neuromonitoring in transcarotid artery revascularization

J Neurointerv Surg. 2024 Feb 20:jnis-2023-021282. doi: 10.1136/jnis-2023-021282. Online ahead of print.

Abstract

Background: In recent years, transcarotid artery revascularization (TCAR) has emerged as a safe and effective alternative to carotid artery stenting. While intraoperative neuromonitoring (IONM) techniques such as electroencephalogram (EEG) and somatosensory evoked potentials (SSEPs) are often employed during TCAR, there is limited research on their diagnostic accuracy.

Methods: The authors retrospectively reviewed a multi-institutional IONM database of TCAR procedures performed with EEG and SSEP monitoring. A total of 516 TCAR procedures were included in this study. Significant changes in EEG and/or SSEPs, surgeon's interventions, resolution of significant changes, and immediate postoperative neurological outcome were documented. Sensitivity, specificity, positive and negative predictive values were calculated.

Results: The incidence of intraoperative onset new neurologic deficit was 0.4%. Significant changes in EEG and/or SSEPs occurred in 5.4% of the cases. Of the cases with IONM alerts, 78.5% returned to baseline with a surgical or hemodynamic intervention. From the cases with unresolved IONM alerts, 33.3% woke up with a new neurological deficit. The overall sensitivity and specificity for IONM was 100% and 99.2%, respectively. The positive predictive value was 33.3% and the negative predictive value was 100%.

Conclusions: IONM during TCAR offers high sensitivity and specificity in predicting postoperative outcome. Patients with resolved IONM alerts had immediate neurological outcomes that were comparable to those who had no IONM alerts.

Keywords: CT Angiography; EEG; Evoked Potentials, Somatosensory; Stent; Stroke.