Intracranial Fusiform Aneurysms: It's Pathogenesis, Clinical Characteristics and Managements

The objective of this study is to investigate clinical characteristics, management methods and possible causes of intracranial fusiform aneurysm.

Out of a series of 2,458 intracranial aneurysms treated surgically or endovascularly, 22 patients were identified who had discrete fusiform aneurysms. Clinical presentations, locations, treatment methods and possible causes of these aneurysms were analyzed.

Ten patients of fusiform aneurysm were presented with hemorrhage, 5 patients with dizziness with/without headache, 4 with ischemic neurologic deficit, and 1 with 6th nerve palsy from mass effect of aneurysm. Two aneurysms were discovered incidentally. Seventeen aneurysms were located in the anterior circulation, other five in the posterior circulation. The most frequent site of fusiform aneurysm was a middle cerebral artery. The aneurysms were treated with clip, and/or wrapping in 7, resection with/without extracranial-intracranial (EC-IC) bypass in 6, proximal occlusion with coils with/without EC-IC bypass in 5, EC-IC bypass only in 1 and conservative treatment in 3 patient. We obtained good outcome in 20 out of 22 patients. The possible causes of fusiform aneurysms were regard as dissection in 16, atherosclerosis in 4 and collagen disease or uncertain in 2 cases.

There is a subset of cerebral aneurysms with discrete fusiform morphology. Although the dissection or injury of internal elastic lamina of the cerebral vessel is proposed as the underlying cause for most of fusiform aneurysm, more study about pathogenesis of these lesions is required.