View of left Meckel’s cave after partial petrosectomy. The tentorium has been cut, and a retractor elevates the temporal lobe to visualize Meckel’s cave and the Gasserian ganglion. The internal carotid artery courses within the petrous bone just inferior to the V3 division of the Gasserian ganglion. Cranial nerve IV runs just medial to the edge of the tentorium in close proximity to the superior cerebellar artery as it wraps around the midbrain. The greater superficial petrosal nerve traverses anteromedially within the petrous temporal bone along the floor of the middle fossa. The transverse pontine vein, the vein of the cerebellar pontine fissure, and the superior petrosal vein are visible here as the venous outflow of the pons. The inferior petrosal sinus runs from the cavernous sinus inferolaterally to the jugular foramen. (Image courtesy of AL Rhoton, Jr.)