Real-Time video-assisted intraoperative neuromonitoring in vestibular schwannoma surgery, Observational 10-year Iranian experience

Abstract

Abstract Background Vestibular schwannoma is an extra-axial, benign tumor that is mostly located in the cerebellopontine angle. The goal of vestibular schwannoma surgery is gross total resection of the tumor along with preservation of the cranial nerves’ function. Intraoperative nerve monitoring is mainly rewarding in VS surgery. Method This study was observed prospectively from 2011–2021. Patients were divided into two groups; group one 19 patients underwent resection of the tumor with intraoperative neuromonitoring and group two without neuromonitoring based on patients’ ability to economically afford neuromonitoring. In the neuromonitoring group, SSEP is evaluated and recorded throughout the whole surgery. MEP is recorded at regular intervals as well. In this study, we benefit from the cooperation of a trained neurophysiologist. We compare tumor size, hemorrhage volume during surgery, length of surgery, and facial nerve preservation (HB score), with the follow-up of 1* year (0, 2, 6 months, 1y). Result FN anatomical preservation rate in the neuromonitoring group was 100% and in the control group was 75%. The rate of GTR in patients operated on using neuromonitoring was 78.9%. The rate of STR and PR in procedures without neuromonitoring was 50.0% and 12.5% respectively. In 100% of patients with intraoperative neuromonitoring, the HB level was evaluated as good. 68.8% of patients without neuromonitoring had poor HB. Conclusion IONM in VS surgery helps increase anatomical nerve preservation rate and facial nerve outcome. The value of coordination of an anatomically trained neurophysiologist along with real-time video-assisted nerve monitoring is to avoid and lower any delay in nerve recognition.