PETROUS INCISIONS FOR TUMORS OF THE CEREBELLOPONTINE ANGLE

Three petrous incisions, performed by an ENT-neurosurgery team, can be used for the resection of tumours of the cerebellopontine angle: transpetrosal incisions (posterior translabyrinthine and transcochlear) which provide large access to the IAM and the posterior surface of the petrous bone, but they sacrifice hearing. The suprapetrosal incision (reserved for tumours in the meatus) and the mastoidoretrosigmoid incision (for tumours less than or equal to 20 mm) preserve the labyrinth in an attempt to preserve hearing. The principal objectives of surgical resection of tumours of the cerebellopontine angle (85 % of which are acoustic neuromas) are total resection (to preserve the vital prognosis) and preservation of facial nerve function. Attempts to preserve hearing must be confined to cases selected by a complete clinical otological and audiometric examination.