Periaqueductal approach to cholesterol granulomas of the petrous apex.

The periaqueductal approach for the drainage of cholesterol granulomas of the petrons apex is described. As with previously reported approaches, the periaqueductal approach takes advantage of the high pneumatization of the temporal bone in this disease. It requires dissection of the supralabyrinthine air cell tract as well as air cells medial to the posterior semicircular canal. This requires a circumferential bony dissection, skeletonization, and preservation of the vestibular aqueduct and the identification of the internal auditory canal. This periaqueductal approach preserves hearing and provides an alternative to the infralabyrinthine and infracochlear approaches when their use is precluded by variations in the temporal bone.