Management of unruptured intracranial aneurysms and arteriovenous malformations.

The natural history and optimal treatment for unruptured cerebral aneurysm and arteriovenous malformations (AVMs) remains unknown. The prevalence of intracranial aneurysms is estimated to be between 1% and 5%. The annual risk of rupture for small aneurysms in the anterior circulation is low. Factors that are associated with increased risk of rupture include location of the aneurysm in the posterior circulation and size of the aneurysm greater than 7 mm in diameter. Management options of unruptured intracranial aneurysms include conservative management, endovascular, or surgical treatment. AVMs are estimated to have a prevalence of 1.4% to 4.3%. The annual risk of rupture of AVMs that did not present with hemorrhage is low at approximately 0.9% per year. Factors that increase the risk of rupture include hemorrhagic presentation, deep AVM location, or deep venous drainage associated with the AVM. The treatment options for AVM available include conservative management, microsurgery, endovascular treatment, radiosurgery, or a combination of methods.