Middle Fossa Approach Application for Pathologies of Temporal Bones and the Cerebellopontine Angle Region

Introduction: Middle fossa approach has proved its usefulness in removal of various pathologies localized within the pyramid of temporal bone as well as in some cases in the cerebellopontine angle region. Good cooperation of the interdisciplinary team, consisting of otologist, neurosurgeon, and anesthesiologist, is one of the conditions to be successful in this type of surgery. Material and Methods: The authors present 20 patients in whom middle fossa approach was applied with pathologies as follows: vestibular nerve schwannoma—12 cases; facial nerve neuroma—3 cases; meningioma of the internal auditory canal—1 case; temporal bone pyramid cholesteatoma—3 cases; selective vestibular nerve section—1 case. In this presentation some anatomical aspects of identification of the temporal bone pyramid landmarks and opening various temporal bone structures were discussed specifically focusing on technical intraoperative difficulties. Results: According to the personal experience of the first author no fewer than two landmarks on the upper surface of the temporal bone pyramid should be identified, preferably the superior semicircular canal and the greater superficial petrosal nerve. If identification of these landmarks was impossible, mostly in pyramid cholesteatoma cases, middle ear ossicles and other bone labyrinth structures served as anatomical points. No serious intraoperative or postoperative complications occurred. The facial nerve paresis worse than third stage, according to the House-Brackmann scale, was found only in 1 vestibular nerve schwannoma case. Postoperative hearing threshold in stage A or B was preserved in 50% of cases. Conclusions: Middle fossa approach is a safe surgical technique providing a good view to the temporal bone pyramid, making possible removal of various pathologies of this region with preservation of neurological and hearing functions.