Transmastoid and middle cranial fossa decompression of the facial nerve in temporal bone fracture

Background: The management of facial nerve injury resulting from temporal bone fracture continues to he a topic of discussion. The indications for surgery as well as the proper timing and extent of surgical exploration are the principal questions debated. Methods: A retrospective review of 7 cases of intratemporal facial nerve injuries following longitudinal temporal bone fracture. This paper discusses pre-operative examination, intra- operative findings and post-operative evaluation. All of them had a positive Schirmer test. Surgery was indicated for patients because they had no response or only a barely discernible response to 10 mA from the Hilger stimulator or greater than 90% degeneration of the facial nerve fibers as measured by electroneuronography. Six patiens underwent total facial nerve decompression using transmastoid and middle cranial fossa approach. One patient with a significant conductive hearing loss underwent transmastoid- extralabyrinthine-subtemporal approach. Results: The most frequent site of injury was the area of the geniculate ganglion. Findings of the facial nerve were swelling, edema, intramural hematoma and bone chip. The injury to the facial nerve was often severe. Conclusions: We recommend early exploration in these cases when electrical studies indicate a severe injury. In most cases a combined mastoid and middle fossa approach is required.