Long term prognosis of symptomatic and asymptomatic cerebral aneurysms.

The authors analyze the follow-up series of 58 patients with diagnosed cerebral aneurysms who were either not treated surgically or, in surgically treated cases, in which the aneurysmal neck was not clipped. The patients are divided in three groups: untreated ruptured; ruptured treated by coating, vessel ligation or aneurysmal dome clipping; and asymptomatic cases. During the follow-up period of three to ten years, there were no bleedings from asymptomatic aneurysms and only one rebleeding from symptomatic operated aneurysms. As can be expected in the group of ruptured unoperated aneurysms, the rate of rebleeding was 40.9% with a mortality rate of 31.7%. The natural history of asymptomatic aneurysms is unclear regarding the risk of bleeding, and regardless of the obtained follow-up results in our cases, we think that all diagnosed cerebral aneurysms must be treated surgically. Certainly, individual cases must be evaluated.