Intraoperative neuromonitoring techniques in the surgical management of acoustic neuromas

Abstract

<jats:p>Unfavorable outcomes such as facial paralysis and deafness were once unfortunate probable complications following resection of acoustic neuromas. However, the implementation of intraoperative neuromonitoring during acoustic neuroma surgery has demonstrated placing more emphasis on quality of life and preserving neurological function. A modern review demonstrates a great degree of recent success in this regard. In facial nerve monitoring, the use of modern electromyography along with improvements in microneurosurgery has significantly improved preservation. Recent studies have evaluated the use of video monitoring as an adjunctive tool to further improve outcomes for patients undergoing surgery. Vestibulocochlear nerve monitoring has also been extensively studied, with the most popular techniques including brainstem auditory evoked potential monitoring, electrocochleography, and direct compound nerve action potential monitoring. Among them, direct recording remains the most promising and preferred monitoring method for functional acoustic preservation. However, when compared with postoperative facial nerve function, the hearing preservation is only maintained at a lower rate. Here, the authors analyze the major intraoperative neuromonitoring techniques available for acoustic neuroma resection.</jats:p>

Influencing Factors Analysis of Facial Nerve Function after the Microsurgical Resection of Acoustic Neuroma

“…Further studies showed that tumor volume was related with the effect of operation13,18,22,25,26). The foreign bulk case studies5,6) displayed that if the tumors were smaller, the postoperative facial nerve function was better.…”

Fehler und Gefahren: Ohrchirurgie und Chirurgie der lateralen Schädelbasis

“…Finden sich stark adhärente Nerven in der Vestibularisschwannomchirurgie, können aber auch bei nur noch geringen Gewebsschichten Stimulationen notwendig sein, die in der Ausdehnung dickere Gewebsschichten zwischen Stimualtionssonde und Nervus facialis erwarten lassen [ 286 ] . [ 280 ] . So wurde berichtet, dass nach der zusätzli-chen intra-und postoperativen Anwendung vasoaktiver Medikamente im Rahmen der Vestibularisschwannomchirurgie das Hörvermögen bei doppelt so vielen Patienten erhalten werden konnte wie ohne zusätzliche medikamentöse Therapie [ 306 ] .…”

Surgery of the ear and the lateral skull base: pitfalls and complications

“…Morbidity was clearly reduced after introduction of intraoperative monitoring into VS surgery [279]. It allows the surgeon to adjust the treatment of VS in a way that allows optimal maintenance of CN function: (i) complete tumour resection, (ii) near-total resection or (iii) a combination of resection and postoperative radiosurgery [280], [281], [282].…”

“…Second, its function may be affected by vascular injury within the internal auditory canal during tumour resection (e.g. vascular occlusion, rupture or spasm) [279]. Accordingly, vasoactive treatment following VS surgery has been associated with a significantly higher rate of hearing preservation [305].…”