Based on the geometry of parent artery,the aneurysms were divided into four subtypes: sidewall aneurysm,sidewall aneurysm with branching vessel,endwall aneurysm, and fusiform aneurysm.

• 依据载瘤动脉几何形状,动脉瘤可分为侧壁动脉瘤、具有分支引流血管的侧壁动脉瘤、顶端动脉瘤和梭形动脉瘤。