Dorsal displacement of the facial nerve in vestibular schwannoma surgery.

Afonso H De Aragão,Ricardo Ramina,Joel Fernando Sanabria Duarte,Gustavo S Jung,Ronaldo Pereira Vosgerau

doi:10.3171/2021.7.focvid2182

Afonso H De Aragão, Ricardo Ramina + Show 3 more

Open Access

https://doi.org/10.3171/2021.7.focvid2182

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Abstract

The course of the facial nerve (FN) has been extensively investigated in patients with vestibular schwannomas (VSs). FN running dorsally to the tumor capsule accounts for less than 3% of the cases. Diffusion tensor imaging (DTI)–based fiber tracking helps to preoperatively identify the FN. During surgery, a higher risk of injury is associated with the dorsal location of the FN. The authors demonstrate the nuances and tricks to identify and preserve a dorsal displaced FN during resection of a large VS, T3b according to the Hannover classification, through the retrosigmoid-transmeatal approach.The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2182

Highlights

This is Dr Gustavo Jung and I’ll demonstrate the microsurgical resection of a vestibular schwannoma with the facial nerve dorsally displaced and the technique to identify the course of the facial nerve during surgery
This 57-year-old male discovered a large vestibular schwannoma during a diagnostic workup for right-side tinnitus. It was classified as a T3b vestibular schwannoma according to the Hannover classification and stage III according to Koos classification
Bimanual dissection with a tumor forceps in nondominant hand and a blunt hook dissector in the dominant hand, the facial nerve is dissected from the tumor capsule all the way to the IAC

Summary

Introduction

This is Dr Gustavo Jung and I’ll demonstrate the microsurgical resection of a vestibular schwannoma with the facial nerve dorsally displaced and the technique to identify the course of the facial nerve during surgery. The patient had an AAOHNS hearing class B and a HouseBrackmann grade I facial nerve function. Facial nerve monitoring and brainstem auditory evoked response were used. The arachnoid membrane is adherent to the dorsal surface of the tumor.

Results

Conclusion