Transmastoid infralabyrinthine approach to petrous temporal bone.

The most direct approach to the anterior and inferior regions of the petrous temporal bone skull base is transmastoid infralabyrinthine. This approach provides an exposure for draining and aerating cholesterol granulomas or obtaining tissue for micropathologic diagnosis. It obviates the exposure of the intracranial space, thereby producing minimal care, as in mastoid-type surgical procedures. The procedure is described and illustrated. Two cases with petrous temporal bone cholesterol granulomas demonstrate the definitive effectiveness of this procedure.