Combined presigmoid retrolabyrinthine and retrosigmoid approach for large vestibular schwannoma: a case report.

BACKGROUND

The retrosigmoid approach is widely used for vestibular schwannoma resection. If the tumor is large, significant cerebellar retraction may be required, which can cause cerebellar edema. The presigmoid retrolabyrinthine route preserves the labyrinth and reduces cerebellar retraction and manipulation but provides only a narrow surgical corridor. We report the use of a combined approach to safely resect a large vestibular schwannoma with brainstem compression while avoiding complete postoperative deafness.

METHODS

A 24-year-old man presented with a large right vestibular schwannoma causing considerable brainstem compression. A combined temporal-suboccipital craniotomy with near-total mastoidectomy was performed to expose the sigmoid sinus while preserving the labyrinth. Microsurgical dissection was performed via the retrosigmoid corridor, while a rigid endoscope inserted through the presigmoid route provided direct visualization of the brainstem side.

RESULTS

This dual-corridor, dual-visualization technique enabled safe subperineural tumor removal and identification of the facial nerve. Gross total resection was achieved, and the postoperative course was uneventful. At approximately 6 months postoperatively, facial nerve function remained normal (House-Brackmann grade I). Formal postoperative pure-tone audiometry demonstrated residual hearing on the operated side, predominantly in the low-frequency range. Although serviceable hearing was not preserved, complete postoperative deafness was avoided.

CONCLUSION

In large vestibular schwannomas with vertical brainstem extension, retrosigmoid resection alone may require excessive cerebellar retraction. Adding a presigmoid retrolabyrinthine corridor improves brainstem access, minimizes cerebellar retraction and manipulation, and facilitates safe tumor removal. This combined approach is a practical strategy for patients with significant brainstem compression.