The superior wall of the cavernous sinus: a microanatomical study

Abstract

The superior wall of the cavernous sinus was studied in 30 specimens obtained from 15 cadaver heads fixed in formalin. Trapezoidal in shape, the superior wall of cavernous sinus is limited laterally by the anterior petroclinoid ligament, medially by the dura of the diaphragma sellae, anteriorly by the endosteal dura of the carotid canal, and posteriorly by the posterior petroclinoid ligament. An interclinoid ligament bisects the wall, dividing it into two triangles: the carotid trigone anteromedially and the oculomotor trigone posterolaterally. Similar to the lateral wall of the cavernous sinus, the superior wall is formed by two layers: a smooth superficial dural layer and a thin, less defined deep layer. In the area of the carotid trigone, both layers separate to wrap the anterior clinoid process. The removal of this process will reveal a "clinoid space" medial to which the internal carotid artery can be identified. This clinoid segment of the artery, still extracavernous, is surrounded by two fibrous rings: a distal ring formed by fibers of the superficial dural layer and a proximal ring related to the deep dural layer. Below the proximal ring, the internal carotid artery becomes intracavernous; above the distal ring, the artery is continuous with its supraclinoid segment. The complex dural anatomy of the superior wall, its fibrous rings, and the clinoid space in relation to a superior surgical approach to the cavernous sinus are discussed.

Differentiation Between Paraclinoid and Cavernous Sinus Aneurysms with Contrast-Enhanced 3D Constructive Interference in Steady- State MR Imaging

“…[12][13][14] Below the proximal ring, the ICA becomes intracavernous; above the distal ring, it is in the CSF and continuous with its supraclinoid segment. [12][13][14] The paraclinoid segment of the carotid artery is defined as the portion between the proximal and distal dural rings, which have a potential space medially, the carotid cave. 12,13 The carotid cave sometimes communicates with the subarachnoid space.…”

Recurrent Alternating Oculomotor Nerve Palsy: An Unusual Presentation of Parasagittal Meningioma

“…Because of the close proximity of these nerves, intracavernous lesions typically give rise to multiple nerve damage rather than an isolated nerve palsy. 5 It should also be noted that the oculomotor trigone, which is defined by the anterior and posterior petroclinoid ligaments, 6 is also a possible site of damage resulting in isolated third cranial nerve palsies. 7 Correspondingly, the parasagittal tumour in the present case was in the midline plane such that compression of the truncus of the corpus callosum may have caused local entrapment of cerebrospinal fluid, causing increased intracranial pressure indirectly compressing the trigonal or cisternal segments of the third cranial nerves in our patient.…”

Anatomical Variations in the Origin of the Human Ophthalmic Artery with Special Reference to the Cavernous Sinus and Surrounding Meninges

“…The origin of the OA varies in relation to the course of the ICA penetrating the cavernous sinus (CS); after the ICA emerges from the carotid canal of the temporal bone, it courses within the cavity of the CS, penetrates the dura mater and enters the subarachnoid space, so that the OA may branch off from any portion along the ICA. A detailed anatomy of the origin of the OA and/or its course has been described in previous reports of cadaver studies [Hayreh and Dass, 1962;Hayreh, 1974;Renn and Rhoton, 1975;Harris and Rhoton, 1976;Maniscalco and Habal, 1978;Gibo et al, 1981;Lang, 1981;Tran-Dinh, 1987;Day, 1989;Inoue et al, 1990;Lang and Kageyama, 1990a, b;Nuza and Taner, 1990;JimenezCastellanos et al, 1993;Umansky et al, 1994].…”

“…For example, subarachnoid hemorrhage might occur due to a rupture of an aneurysm at the branching point of the OA from the ICA, or a carotid-cavernous fistula might be caused by either a ruptured aneurysm in the CS cavity or dural arteriovenous malformation at the CS wall. Particular approaches and techniques have been recommended for the direct operation of a lesion of the ICA within the CS cavity or at the CS roof, including an aneurysm arising at the OA origin [Parkinson, 1965;Harris and Rhoton, 1976;Gibo et al, 1981;Dolenc, 1985;Perneczky et al, 1985;Day, 1989;Kobayashi et al, 1989;Inoue et al, 1990;Ohmoto et al, 1991;Krisht et al, 1994;Umansky et al, 1994]. It is still important for neurosurgeons to have detailed information of the possible anatomical variations when operating on such cases.…”