Unruptured Intracranial Aneurysms and Multiple Aneurysms: Natural History and Treatment Options

Surgery on unruptured intracranial aneurysms (UIAs) could be a good strategy for prevention of haemorrhage, but management decisions require an accurate assessment of the risks of various treatment options, compared with the natural history of subarachnoid haemorrhage (SAH). The International Study for Unruptured Aneurysms (ISUIA) showed that the natural history is different for patients with UIAs who have not experienced SAH, than it is for patients with a history of prior SAH due to a separate aneurysm, in whom the risk is increased. The size of the UIAs is the best predictor of future rupture and the site can also be. The role of elective neuroradiological screening is the subject of discussion. In fact, the possibility of treatment should be considered on the basis of the patient's age and clinical status. Factors that favour surgery include a young patient with a long life expectancy, previously ruptured aneurysms, a familiarity, large and symptomatic aneurysms and low risk of treatment. The role of endovascular treatment is also discussed.