The cavernous sinus (CS) is a complex venous space that lies on the lateral sides of the sella turcica surrounded by the meningeal and periosteal dural folds. The sinus extends from the superior orbital fissure to the apex of the petrous temporal bone, with an average length of 2 cm and a width of 1 cm. The internal carotid artery (ICA), with the sympathetic plexus around it, passes forward through the sinus together with the abducens nerve (VI) which lies lateral to the artery. The oculomotor (III) and trochlear nerves (IV) and the ophthalmic (V1) and maxillary divisions (V2) of the trigeminal nerve all lie in the lateral wall of the sinus. [1] The lateral wall of the CS has two layers; the external layer is thick and pearly grey, and the internal is semitransparent and contains the cranial nerves. These layers can be surgically separated to expose the III, IV and V1. The medial wall of the CS has two areas, sellar and sphenoidal, both of which are made up of one dural layer only. The superior wall, also called the CS roof, is formed by three triangles: oculomotor, clinoid and carotid triangles. CN III is located in a cisternal space in the oculomotor triangle. The posterior wall is part of the dura that covers the clivus, made up of the meningeal and periosteal dural layers. This wall is close to the vertical segment of the abducens nerve (VI), from the point of its dural perforation to where it changes direction at the level of Dorello's canal. The cavernous segment of the ICA with its accompanying sympathetic neural plexus continues just medial to the CN VI. The ICA and CN VI pass through the CS sinusoids.[2] Cranial nerves III, IV, and V1 exit the cranium through the superior orbital fissure, the V2 exits the cranium through the foramen rotundum.The anatomical structures of the CS can be invaded by neoplastic, infectious, inflammatory, and vascular lesions. There are two ways of approaching the CS, intradural, with access to the CS via its dural roof through the anteromedial or medial triangle; and extradural, with access to the CS through its lateral wall, through the paramedial, Parkinson's, anterolateral or lateral triangles after surgically separating the two dural layers and identifying CN III, IV, and V. A posterior approach is also possible, though very difficult. [3,4] The choice of surgical approach depends mainly on the location of the lesion and its nature.A precise knowledge of the complex anatomy of the CS, together with pathological processes and their imaging characteristics will enable accurate evaluations of the conditions that affect the CS. This article presents a model (coffee cup model) of the CS that enables us to learn morphological features of the CS.
Coffee cup model of the cavernous sinus
Leonard KranzlerDepartment of Neurological Surgery, University of Chicago, Chicago, IL, USA
AbstractThe cavernous sinuses are complicated venous structures comprising important neurovascular structures, the internal carotid artery and the oculomotor, trochlear, ophthalmic, maxillary and abducens n...