Surgical prognosis of unruptured cerebral aneurysms. Report of 40 cases in University Hospital Zurich.

A series of 40 patients admitted to University Hospital Zurich (1996-97) with unruptured cerebral aneurysms is reported. Fifty-two aneurysms were treated in 40 operations. The age of surgically treated patients ranged from 31 to 78 year old (mean 53.6). The main locations of the aneurysms were: MCA 21 (40.4%), AcomA 10 (19.2%), ICA (posterior communicating and bifurcation) 6 (11.5%), carotid-ophthalmic segment 4 (7.7%), ACA 4 (7.7%), basilar tip 3 (5.8%), vertebral artery 2 (3.8%). The circumstances of diagnosis were: incidental 15 (37.5%), other cranial lesions 9 (22.5%), symptomatic 8 (20%), multiple aneurysm 8 (20%). The overall outcome of surgery was: good recovery in 39 cases (97.5%), moderately disabled in 1 case (2.5%) who was 56 year-old and had three aneurysms including basilar tip. There was no operative mortality. Though this series has small number of patients, it suggests that location of the aneurysm is an important factor affecting surgical outcome among patient age, the circumstances of the diagnosis, size and location of aneurysm.