Open AccessDistinction between Paraclinoid and Cavernous Sinus Aneurysms with Computed Tomographic Angiography
Author(s) -
L. Fernando Gonzalez,
Matthew T. Walker,
Joseph M. Zabramski,
Shahram Partovi,
Robert C. Wallace,
Robert F. Spetzler
Publication year - 2003
Publication title -
neurosurgery/neurosurgery online
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.485
H-Index - 34
eISSN - 1081-1281
pISSN - 0148-396X
DOI - 10.1093/neurosurgery/52.5.1131
Subject(s) - medicine , internal carotid artery , cadaveric spasm , aneurysm , cavernous sinus , optic nerve , optic canal , radiology , angiography , sinus (botany) , anatomy , anterior clinoid process , botany , biology , genus
OBJECTIVE To examine the reliability of using the optic strut as a landmark in computed tomographic (CT) angiography, to differentiate between intradural and extradural (cavernous sinus) aneurysms involving the paraclinoid segment of the internal carotid artery (ICA). METHODS Microanatomic dissections were performed with five cadaveric heads (10 sides), to establish the relationships of the optic strut to the cavernous sinus and the ICA. Results from these anatomic studies were compared with intraoperative and CT angiographic findings for four patients with nine intracranial aneurysms involving the paraclinoid segment of the ICA. RESULTS The inferior boundary of the optic strut accurately localized the point at which the ICA pierced the oculomotor membrane (proximal dural ring) and exited the cavernous sinus. The optic strut and its relationship to the ICA could be well observed on CT angiograms. During surgery, six of six aneurysms that arose distal to the optic strut were identified intradurally and were successfully clipped. Conversely, all aneurysms that arose proximal to the optic strut were observed to lie within the cavernous sinus. An aneurysm at the optic strut was within the clinoid segment or interdural, between the proximal and distal rings. CONCLUSION The optic strut, as identified with CT angiography, provided a reliable anatomic landmark for accurate discrimination between intradural and extradural (cavernous sinus) aneurysms.