Giant and large peripheral cerebral aneurysms: etiopathologic considerations, endovascular treatment, and long-term follow-up.

BACKGROUND AND PURPOSE Giant/large peripheral cerebral aneurysms beyond the circle of Willis and middle cerebral artery (MCA) bifurcation are rare lesions, their etiopathogenesis is not completely elucidated, and their treatment is often difficult. We reviewed the etiopathologic findings available in the literature and report the results and long-term follow-up in 10 patients with a giant/large peripheral aneurysm treated by parent artery occlusion. METHODS Four aneurysms were on the MCA, 2 on the anterior cerebral artery, and 4 on the posterior cerebral artery (PCA). Two patients presented with bleeding. An occlusion test was performed in 7 patients. Occlusion of the parent artery was performed by using coils in 8 patients; and liquid coils and glue, in 2. Imaging follow-up was available from 1.5 to 4.5 years; and clinical outcome, from 1.5 to 7 years. RESULTS All aneurysms were excluded. One patient developed a partial homonymous hemianopsia after PCA occlusion. A transient deficit was observed in 2 other patients. In the partially thrombosed aneurysms, follow-up imaging showed shrinkage of the thrombosed compartment of the aneurysm and disappearance of the mass effect. No patient experienced progression of symptoms and/or bleeding during the follow-up period. At long-term follow-up, 6 patients presented with a modified Rankin Scale score of 0; 3, with score of 1; and 1, with score of 2. CONCLUSION The endovascular occlusion of the parent artery appears a relatively safe and efficacious technique in the treatment of these lesions. Long-term follow-up studies confirm persistent exclusion of the aneurysm and good clinical tolerance to the vessel occlusion.