[Unruptured intracranial saccular aneurysms less than 20 mm in diameter in adults. Radical surgery in 89 cases].

Between 1972 and 1989, 131 unruptured intracranial saccular aneurysms were clipped in the Neurosurgical Department of La Pitié Hospital, Paris. Only 89 of these are considered here, the remaining 42 aneurysms having been discovered and clipped during surgery for a ruptured aneurysm. All isolated unruptured aneurysms were detected by angiography, computerized tomography or magnetic resonance imaging. Twenty out of the 89 aneurysms were asymptomatic ("incidental") while 69 were accompanied by clinical symptoms indicating radiological examination. It is generally accepted that in ruptured aneurysms the mortality rate during 3 days following the rupture is about 50 percent, and for this reason many neurosurgeons are in favour of unruptured aneurysms being treated either by open surgery with clipping of the aneurysmal neck or by inserting a balloon into the aneurysmal sac. The results obtained in 377 published cases, including ours, justify this approach: no recurrent bleeding was observed after open surgery and the mortality rate was nil when the contra-indications of surgery were respected. There was a permanent morbidity of less than 2 per cent directly related to the surgeon's experience.