The medial wall of the cavernous sinus. Part 1: Surgical anatomy, ligaments, and surgical technique for its mobilization and/or resection

OBJECTIVEThe medial wall of the cavernous sinus (CS) is often invaded by pituitary adenomas. Surgical mobilization and/or removal of the medial wall remains a challenge.METHODSEndoscopic endonasal dissection was performed in 20 human cadaver heads. The configuration of the medial wall, its relationship to the internal carotid artery (ICA), and the ligamentous connections in between them were investigated in 40 CSs.RESULTSThe medial wall of the CS was confirmed to be an intact single layer of dura that is distinct from the capsule of the pituitary gland and the periosteal layer that forms the anterior wall of the CS. In 32.5% of hemispheres, the medial wall was indented by and/or well adhered to the cavernous ICA. The authors identified multiple ligamentous fibers that anchored the medial wall to other walls of the CS and/or to specific ICA segments. These parasellar ligaments were classified into 4 groups: 1) caroticoclinoid ligament, spanning from the medial wall and the middle clinoid toward the clinoid...