Combined Middle Cranial Fossa/Transmastoid/Retrosigmoid Resection of Facial Nerve Schwannoma with Hearing Preservation

Introduction: The optimal management paradigm of facial nerve schwannomas remains controversial, with observation, resection, and radiosurgery all being utilized. Commonly, tumors are observed until facial function declines. Rarely, patients with large tumors with intracranial extension may retain good facial function and hearing ability. These patients, especially when young, present a dilemma, as the risks of unchecked tumor growth and central nervous system mass effect must be weighed against the morbidity of resection to the facial nerve and hearing. In this study, we describe a combined surgical approach with hearing preservation and a unique facial “pre”-animation strategy for a large facial nerve schwannoma.

Methods: A 21-year-old male with normal hearing and normal facial nerve function presented with a large (17 mm) facial nerve schwannoma with extension into both the posterior and middle fossae. In preparation for facial nerve transection, he underwent masseteric to facial nerve transfer 6 months prior to a combined middle fossa, retrosigmoid, and transmastoid resection with cable grafting of the facial nerve defect with cadaveric nerve. He underwent tarsorrhaphy and upper eyelid gold weight placement 3 weeks after surgery.

Results: At the time of his last follow-up, 10 months after surgery, he was found to have HB 3 facial nerve function and complete hearing preservation. He is currently being treated with botulinum toxin for synkinesis. In addition, there is no evidence of residual/recurrent tumor.

Conclusion: A combined middle fossa, retrosigmoid, and transmastoid approach can afford a complete resection of large facial nerve schwannomas with hearing preservation. A pre-operative masseteric to facial nerve transfer can minimize the length of time patients must suffer facial weakness in those whom complete, gross-total resection of a facial nerve schwannoma is planned.

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Artikel online veröffentlicht:
15. Februar 2022