Large and Giant Paraclinoid Aneurysms Treated by Combined Extradural and Intradural Approach

ABSTRACT

Between May, 1992 and April, 1993, four patients with paraclinoid aneurysms were treated by a direct operative approach. Two patients had large aneurysms, all of which had ruptured, presented with subarachnoid hemorrhage(SAH). The other two patients had giant aneurysms, causing visual symptoms by optic nerve compression. All patients were treated by a combined extradural and intradural approach. All the aneurysms were successfully clipped and collapsed or resected, eliminating the risk of rebleeding and decompressing the visual system immediately and effectively, while preserving the blood flow of the carotid artery and its branches. Removal of the individual bony structure including anterior clinoid process(ACP) and orbital roof at the skull base extradurally provides a better and safer exposure of the aneurysm, and of the ophthalmic segment of the carotid artery than does excessive retraction of the brain. This technique also affords exposure of the internal carotid artery proximal to the lesion and ophthalmic artery, which is important in securing safe and complete occlusion of the aneurysm. Authors present operative technique, summary of cases, and literature review.