Preauricular Subtemporal-Infratemporal Fossa Approach to the Petrous Carotid. E, The mandibular condyle has been pushed downward and a frontotemporal craniotomy has been completed. The dura of the lateral wall of the cavernous sinus has been elevated. The floor of the middle fossa has been resected down to the level of the tensor tympani muscle and eustachian tube and the posterior vertical segment and posterior genu of the petrous carotid artery. The posterior cerebral and superior cerebellar arteries have been exposed. The lateral walls of the sphenoid sinus have been opened by removing bone between the trigeminal divisions. F, The eustachian tube and tensor tympani have been resected to expose the horizontal segment of the petrous carotid. G, The petrous carotid has been reflected forward out of the carotid canal to expose the petrous apex. H, The petrous apex and adjacent part of the clivus medial to the jugular foramen have been removed and the posterior fossa dura opened to expose the junction of the vertebral and basilar arteries and the origin of the anterior inferior cerebellar artery. (Images courtesy of AL Rhoton, Jr.)