Double bilateral symmetrical aneurysms--case report.

A 52-year-old female admitted for subarachnoid hemorrhage and preoperative angiography revealed bilateral symmetrical middle cerebral artery aneurysms, which were successfully clipped. Post-operative angiography revealed bilateral symmetrical aneurysms in the distal anterior cerebral arteries, which were not identified on the preoperative angiograms, and were also clipped successfully. Such multiple aneurysms should not be treated by bilateral approaches in a one-stage operation.