Surgical Landmarks for the Internal Carotid Artery in Endoscopic Endonasal Approaches. A, 0-degree view. The Eustachian tube and the fossa of Rosenmüller are identified. The mucosal layer, the superior constrictor muscle at the posterior wall of the nasopharynx, and the basopharyngeal fascia as well as the longus capitis muscle have been removed on the left side. B–E, 45-degree view directed at the left side. B and C, The rectus capitis anterior muscle has been identified and reflected inferiorly. This maneuver exposes the capsule of the atlanto-occipital joint medially and the carotid sheath laterally. D and E, The carotid sheath has been opened and the parapharyngeal ICA identified. F, 0-degree view in another specimen. The clivus has been exposed after removing the mucosa, basopharyngeal fascia, Eustachian tube, and prevertebral muscles. (Images courtesy of AL Rhoton, Jr.)