床突段动脉瘤( clinoidal segment aneurysms , Clin Seg aneurysms )可以分为前外侧型( anterolateral variant )床突段动脉瘤和内侧型( medial variant )床突段动脉瘤两种亚型。前外侧型床突段动脉瘤起源于床突下,斜向上方硬脑膜环的颈内动脉前外侧方,动脉瘤指向上方在颈内动脉前外侧面。内侧型床突段动脉瘤由该段颈内动脉内侧发出,向蝶窦和蝶鞍膨胀生长。有时小型内侧型床突段动脉瘤由颈内动脉近端向下生长,很难与垂体上动脉或颈动脉陷窝动脉 ......