Extradural Surgical Approach to the Petrous Bone by the Subtemporal Trepanation S u m m a r y: The author reports personal experiences with operations of traumatic or tumorous destructive lesions of the petrous bone in 26 patients. Neurosurgical extradural middle fossa approach is recomended especially in cases of purulent or malignant origin. The extradural middle fossa approach facilitate the overview of the upper surface of the pyramid. The healing of subtem- poral trepanation is uneventfull and the using the local anesthesia is possible.

        Key words: skull base surgery, extradural approach, middle fossa approach, petrous bone tumor, cholesteatoma, epidermoid cyst, CSF otorrhoea, petrous apex.