Zusammenfassung
Hintergrund
Bei Operationen an Vestibularisschwannomen gehören Schädigungen des N. facialis mit konsekutiven funktionellen Defiziten zu den bedeutendsten Komplikationen. Die intraoperative Funktionsüberwachung soll dazu dienen, diese Komplikation zu vermeiden.
Fragestellung
Welche Methoden zur intraoperativen Funktionsüberwachung haben sich entwickelt? Welche Methoden sind aktuell in Gebrauch, und welche Ziele können damit sinnvoll verfolgt werden?
Material und Methoden
Auswertung und Zusammenfassung der Literatur, Diskussion der vorhandenen Methoden und ihrer Fähigkeiten, die gesteckten Ziele zu erreichen.
Ergebnisse
Die intraoperative Funktionsüberwachung soll es ermöglichen, den N. facialis intraoperativ sicher zu identifizieren. Sie soll potenziell schädigende Ereignisse anzeigen und während der Operation eine Einschätzung über den zu erwartenden postoperativen Funktionszustand des Nervs erlauben. Zur Verfügung stehen die elektrische Direktstimulation, das freilaufende Elektromyogramm (EMG), evozierte Potenziale des N. facialis und das prozessierte EMG.
Schlussfolgerungen
Die Identifikation und Verfolgung des Nervs im Operationssitus mittels der elektrischen Direktstimulation ist gut möglich. Potenziell schädigende Ereignisse können mit allen anderen Methoden in Echtzeit oder nahezu in Echtzeit angezeigt werden. Die intraoperative Prognostik wird derzeit aber bei allen verfügbaren Methoden durch falsch-positive Untersuchungsergebnisse belastet und ist nur bedingt verlässlich.
Abstract
Background
In vestibular schwannoma surgery, facial nerve injury with consecutive functional impairment is one of the most important complications. Intraoperative monitoring of facial nerve function has been developed in order to avoid this complication.
Objective
Which methods for intraoperative monitoring have been developed? Which methods are in use today and what can they achieve in modern vestibular schwannoma surgery?
Material and methods
This article provides an evaluation and summary of the literature, as well as a discussion of the methods and their ability to achieve the goals of intraoperative monitoring.
Results
Intraoperative functional monitoring aims to identify and map the facial nerve in the surgical field during surgery. It also aims to identify potentially damaging events and allow for intraoperative prognosis of functional outcome. Available methods are direct electrical stimulation, free-running electromyogram (EMG), facial nerve evoked potentials, and processed EMG.
Conclusion
Identification and mapping of the facial nerve in the surgical field can be reliably achieved by direct electrical stimulation; potentially dangerous events can be identified in real time by the free-running EMG and the processed EMG, and almost in real time by facial nerve evoked potentials. Intraoperative prognostics are hampered by false-positive results with all available methods and have limited reliability.
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J. Prell, C. Strauss, S. K. Plontke und S. Rampp geben an, dass kein Interessenkonflikt besteht.
Dieser Beitrag beinhaltet keine von den Autoren durchgeführten Studien an Menschen oder Tieren.
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Prell, J., Strauss, C., Plontke, S.K. et al. Intraoperative Funktionsüberwachung des N. facialis. HNO 65, 404–412 (2017). https://doi.org/10.1007/s00106-017-0340-1
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DOI: https://doi.org/10.1007/s00106-017-0340-1