Ujiie H, Sato K, Onda H, Oikawa A, Kagawa M, Takakura K, Kobayashi N
Department of Neurosurgery and Neuroradiology, Tokyo Women's Medical College, Japan.
Stroke. 1993 Dec;24(12):1850-6. doi: 10.1161/01.str.24.12.1850.
We analyzed the risk factors for rupture of an intracranial aneurysm based on a retrospective angiographic study of ruptured and unruptured aneurysms.
The 44 cases of asymptomatic aneurysms were selected from 1612 patients whose lesions had been discovered fortuitously by angiography (2.7%) during the period from 1980 to 1989. All these patients were free from any sign of intracranial aneurysm. The variations in age, sex, and location of the aneurysms were analyzed compared with 638 ruptured aneurysms that had been treated in our institute during the same period. The size, shape, and arterial geometry of the unruptured aneurysms were examined angiographically.
Unruptured aneurysm was discovered fortuitously in 44 (2.7%) of 1612 patients, with greater incidence in women aged older than 60 years. Unruptured aneurysms were less likely to occur in the anterior communicating artery (12.8%) and the middle cerebral artery (6.4%). However, they were frequently found in the internal carotid artery, with an incidence of 10.6% in cavernous portion of the internal carotid artery, 19.1% in the internal carotid-ophthalmic artery, 19.1% in the internal carotid-posterior communicating artery, and 12.8% in the internal carotid-anterior choroidal artery. Seven of the nine internal carotid-posterior communicating artery aneurysms showed a hypoplastic or aplastic posterior communicating artery. The mean diameter of the unruptured aneurysms was 4.8 mm, and 80% were smaller than 6 mm.
Intracranial aneurysms are formed not only at the bifurcation of an artery but also at its branching and bending points. However, an aneurysm located at the bifurcation, such as the anterior communicating artery and the middle cerebral artery, bleeds easily in contrast with lateral aneurysms such as those found at the branching and bending points on the internal carotid artery.
我们基于一项对破裂和未破裂颅内动脉瘤的回顾性血管造影研究，分析了颅内动脉瘤破裂的危险因素。
从1980年至1989年期间因血管造影偶然发现病变的1612例患者中选取44例无症状动脉瘤患者（占2.7%）。所有这些患者均无颅内动脉瘤的任何体征。将这些动脉瘤患者的年龄、性别和位置变化与同期在我院治疗的638例破裂动脉瘤进行分析比较。对未破裂动脉瘤的大小、形状和动脉几何学特征进行血管造影检查。
在1612例患者中偶然发现44例（占2.7%）未破裂动脉瘤，60岁以上女性发病率更高。未破裂动脉瘤在前交通动脉（12.8%）和大脑中动脉（6.4%）的发生率较低。然而，它们常在内颈动脉发现，在内颈动脉海绵窦段发生率为10.6%，在内颈动脉眼动脉段为19.1%，在内颈动脉后交通动脉段为19.1%以及在内颈动脉脉络膜前动脉段为12.8%。9例颈内动脉后交通动脉瘤中有7例显示后交通动脉发育不全或未发育。未破裂动脉瘤的平均直径为4.8mm，80%小于6mm。
颅内动脉瘤不仅形成于动脉分叉处，也形成于其分支和弯曲点。然而，位于分叉处的动脉瘤，如前交通动脉和大脑中动脉的动脉瘤，与位于颈内动脉分支和弯曲点等外侧的动脉瘤相比，更容易出血。
