[Acoustic Neuroma:Surgical Strategy Using Intraoperative Monitoring and Trend Graphs from the Neurosurgery Perspective].

Abstract

This study assessed the efficacy of combining preoperative three-dimensional (3D) fusion imaging with continuous intraoperative neurophysiological monitoring to enhance the anatomical and functional visualization of cochlear and facial nerves during acoustic neuroma surgery. Data from 282 consecutive patients (2006-2023) were analyzed. In all cases, dorsal cochlear nucleus action potential (DNAP) and facial nerve root evoked electromyography (FREMAP) were continuously monitored. A novel system was implemented for real-time waveform visualization, tracking amplitude trends, and displaying nerve preservation rates, allowing for immediate identification of neural deterioration, causative maneuvers, and responses to surgical interventions. Preoperative 3D fusion imaging was performed in 199 cases, and nerve trajectory visualization was achieved in 65% of these cases. A comprehensive database integrating clinical and intraoperative data was created, and multivariate analyses was performed to identify predictors of postoperative function. Final DNAP and FREMAP preservation rates were significantly associated with hearing and facial nerve outcomes, respectively. Optimal DNAP and FREMAP thresholds, as determined using receiver operating characteristic (ROC) analysis, were ≥ 35.5% and ≥ 58.5%, respectively. These findings support the utility of real-time, continuous neurophysiological monitoring and preoperative imaging in improving nerve preservation. The surgical techniques and monitoring strategies are demonstrated in the accompanying video.