Risk factors for multiple intracranial aneurysms rupture: a retrospective study

The presence of predicting the rupture risk of intracranial aneurysms has recently generated considerable controversy. We retrospectively investigated the risk factors for multiple intracranial aneurysms related to rupture.

Between July 2007 and July 2011, 134 patients with 294 aneurysms were identified after review. Every patient had two or more aneurysms. Univariate and multivariate logistic regression models were used to analyze the risk factors for multiple intracranial aneurysms with age, gender, site and size.

134 patients were divided into three groups according to patient age category (<45, 45-65, >65 years of age). The incidence of aneurysms ruptured in the second group was significantly higher. Three groups showed significant difference (P=0.001 versus >65 years of age). Thirteen of 35 AComA aneurysms were ruptured, accounting for 26% of all ruptured aneurysms, and the rate of rupture at AComA aneurysms in patients was 37.1%. The rate of aneurysm rupture in the AComA was significantly higher than that in other sites (P=0.001). In all 294 aneurysms, 88.1% of the aneurysms were 5mm or less, of which 58.2% were less than 3mm. In the ruptured aneurysms, 68% were 5mm or less.

Our study reveals the pattern of ruptured multiple intracranial aneurysms, in terms of age, size and location of aneurysms. Age, size, and site of aneurysm should be considered in the decision whether to treat an unruptured aneurysm or not. Especially, in cases of multiple aneurysm, the AComA aneurysm is most prone to hemorrhage.