Risk of bleeding from unruptured aneurysm in cases with multiple intracranial aneurysms.

The author presents a follow-up review of 61 patients with subarachnoid hemorrhage (SAH) and at least two intracranial artery aneurysms in whom only the ruptured aneurysm had been clipped. During a 10-year follow-up period, seven patients bled from a previously unruptured aneurysm; four of the hemorrhages were fatal. Three additional patients suffered fatal bleeding more than 10 years after the first SAH. The surgical mortality rate when operating on a ruptured aneurysm at this clinic was 4.2% in 1979. Considering that the mortality rate after rebleeding during an average follow-up period of 16 years was 11.5%, operation for unruptured aneurysms seems to have a slight edge over conservative treatment.