TRANSCOCHLEAR TRANSTENTORIAL APPROACH FOR REMOVAL OF LARGE CEREBELLOPONTINE ANGLE MENINGIOMAS

Meningiomas of the cerebellopontine angle (CPA) most often arise from the posterior surface of the petrous pyramid and may extend along the dura to involve the tentorium. Petroclival meningiomas often involve Meckel's cavity and the tentorium. It is impossible to completely remove these large lesions with extension to the supratentorial region by conventional surgical approaches to the CPA such as the suboccipital, middle fossa, or translabyrinthine routes. If total tumor resection is not accomplished, recurrence inevitably follows. A transcochlear approach and actual excision of a large portion of the tentorium allows wide exposure to these large CPA and petroclival meningiomas with supratentorial extension. Thirty-three CPA meningiomas were reviewed from 1976 to 1991. Fourteen patients had tumor extension not only into Meckel's cavity but to the supratentorial region. Ten patients had complete tumor removal, whereas subtotal removal was associated with cavernous sinus invasion. The surgical technique is described in detail with accompanying illustrations. Preoperative symptoms, medical imaging scans, results, and complications are discussed.