Clinical manifestations and surgical results for paraclinoid cerebral aneurysms presenting with visual symptoms

Clipping a paraclinoid aneurysm is difficult if the patient has a visual disturbance. Visual function sometimes deteriorates postoperatively for patients with a large aneurysm. In this study, we report the long-term follow-up of patients with visual impairments attributed to optic nerve compression when paraclinoid aneurysms are surgically treated.

Seventeen patients with optic nerve impairment induced by compression of paraclinoid ICA aneurysms were treated. All of the aneurysms were large, including 6 giant aneurysms. The aneurysms displayed partial thrombosis or calcification of the aneurysmal wall in 6 cases.

Direct surgery such as neck clipping or wrapping of the aneurysm was performed in 9 aneurysms and indirect procedures in 8 others (ICA occlusion, 1; ICA occlusion + bypass, 7). Of 17 patients, 11 (65%) showed improvement in several dysfunctions of visual acuity or visual field. Of 6 patients, whose vision had not recovered well, 5 underwent direct surgery. Moreover, these 5 patients had an intra-aneurysmal thrombosis or calcification of the aneurysmal wall. Nevertheless, 1 patient whose aneurysm with partial thrombosis was treated via indirect procedure had good recovery of vision.

Direct clipping is the treatment of choice for patients with a mass effect on the optic nerve due to paraclinoid aneurysm. However, it is difficult to achieve sufficient decompression of the optic nerve when the aneurysm is accompanied by partial thrombosis or calcification of the aneurysmal wall. In those cases, an indirect procedure seems to be a relatively safe, effective treatment.