Surgical strategies for giant intracranial aneurysms.

Untreated giant intracranial aneurysms have a dismal natural history as a result of hemorrhage, cerebral compression, and thromboembolism. The poor prognosis of patients with giant aneurysms therefore warrants aggressive treatment. A surgical approach is chosen to maximize the operative exposure of the aneurysm and depends mainly on the aneurysm's location. Once exposed, vascular control of the aneurysm is required not only to manage an intraoperative rupture, but also to collapse the aneurysm, to increase working space, and to improve visualization of the anatomy. Hypothermic circulatory arrest may be indicated in select patients with complex posterior circulation aneurysms. Direct clipping of giant aneurysms, with meticulous preservation of parent and branch arteries, is the preferred method of occlusion. Unclippable aneurysms require alternative techniques (e.g., trapping, parent artery occlusion, excision, and aneurysmorrhaphy) that compromise parent arteries and may require revascularization to restore adequate cerebral blood flow. Giant aneurysms are complex lesions that demand thorough surgical planning, individualized strategies, and a multidisciplinary effort in specialized neurovascular centers.