[Anatomicopathological relation between facial nerve and large vestibular Schwannoma].

OBJECTIVE: To study the anatomicopathological relation between facial nerve and large vestibular schwannoma. METHODS: Operation by suboccipital retrosigmoid sinus approach was performed on 40 cases with large vestibular schwannoma, During the operation, the anatomicopathological relation between the facial nerve and the vestibular schwannoma was observed directly. RESULTS: The facial nerve was found to be located ventrally (deep under the tumor), dorsally (over the tumor), at the upper pole of the tumor (near the tentorium cerebelli), at the lower pole of the tumor (near the rear group cranial nerves), or aberrant (unable to be identified because of infiltration of tumor). In 31 cases, mainly with parenchymatous tumor, the facial nerve was flat in shape. In 9 cases, mainly with cystic tumor, the facial nerve was bandlike. CONCLUSION: The facial nerve varies greatly in neuroanatomy among patients with large vestibular schwannoma. Strengthening of operative monitoring can increase the safety of operation.