Learning Objectives: We will show the benefit of the transonic approach as a safe procedure to preserve facial nerve function, to achieve total resection and to prevent complications, in cases of Petrous Bone Cholesteatoma.

Petrous Bone Cholesteatoma is a life threatening condition. Acquired or congenital in origin, is one of the most challenging intratemporal lesions.

Depply located inside the petrous portion of the temporal bone the difficulty to manage this lesions is conditioned by the involvement of structures like the otic capsule, the facial nerve, the dura, the internal auditory canal, the sigmoid sinus, the jugular bulb or the internal carotid artery.

Techniques that include subtotal petrosectomy are commonly associated to prevent future infections. Preservation of hearing is not a reasonable objective in many cases if total resection should be accomplished. The transtic approach with elimination of the anterior and posterior otic capsule leaving the facial nerve in place, adapts to some of this challenging lesions.

We report on a series of 60 Petrous Bone Cholesteatoma A Modified Sanna Classification is used to define the location and extension of the lesions.

We will report on hearing function, facial nerve function and complications.

We will focuss on those cases in which we have used the transotic approach to preserve anatomically and functionally the facial nerve.