Unruptured Intracranial Aneurysms : Review of Natural History and Recommended Management Strategies

Unruptured intracranial aneurysms (UIA) are common and in the absence of evidence from randomized controlled trials, management decision can be difficult. However with the various well-planned meta-analyses, certain guidelines can be formulated for risk assessment and surgical management. UIA in patients aged more than 64 years irrespective of size, and those measuring less than 10mm in the maximum diameter should be treated conservatively, but should be evaluated yearly with MR angiography or CT angiography to look for rapid increase in size. UIA showing a diameter increase of more than 0.95mm in a year should be treated by surgery or endovascular therapy. Surgery is indicated for all UIA measuring more than 10mm in maximum diameter in patients aged less than 64 years. Endovascular therapy is indicated for UIA, which need intervention but are not surgically accessible or where surgery is contraindicated due to high-risk medical factors.