The Size of Ruptured Intracranial Aneurysms : A 10-Year Series from a Single Center.

PURPOSE: There is a controversy concerning the risk of rupture of small intracranial aneurysms. We sought to determine the size and morphological features of ruptured intracranial aneurysms.

MATERIAL AND METHODS: The hospital files and images from all patients referred during one decade (2007-2016) to a specialized neurovascular center were retrospectively reviewed. Neck diameter, fundus depth and width as well as neck width based on catheter angiography were measured. Aneurysm morphology was classified as either regular, lobulated, irregular or fusiform.

RESULTS: A total of 694 consecutive patients with aneurysmal subarachnoid hemorrhage (aSAH) were identified (65.9% female, median age 54.3 years). The anterior communicating artery (AcomA) was the most frequent location of ruptured aneurysms. The medians for aneurysm depth, width and neck diameter were 5 mm, 4.5 mm and 3 mm, respectively. A regular contour of the aneurysm sac was found in 19%.

CONCLUSION: The majority of aSAH are caused by small intracranial aneurysms. There is no safety margin in terms of small aneurysm size of regular shape without daughter aneurysms. Treatment should also be offered to patients with small, regularly shaped intracranial aneurysms, together with an empirical risk-benefit assessment.