E, The bony capsule around the semicircular canals and the facial nerve have been exposed for the retrolabyrinthine variant of the presigmoid approach. F, The exposure with the retrolabyrinthine version does not differ significantly from that achieved with the minimal mastoidectomy. G, The semicircular canals and vestibule have been removed and the dura lining the internal acoustic meatus has been opened to complete the translabyrinthine exposure. This yields an exposure of the internal acoustic meatus but provides only minimal improvement in the exposure of the structures medial to the porus of the meatus. H, The nerves have been separated beginning laterally at the fundus of the meatus and extending the cleavage plane medially toward the brainstem. The superior vestibular nerve is behind the facial nerve and the inferior vestibular nerve is behind the cochlear nerve. (Images courtesy of AL Rhoton, Jr.)