著者

貫井 英明 長屋 孝雄 宮城 修 玉田 潤平 金子 的実 佐々木 秀夫 三塚 繁 川渕 純一 河野 徳雄 苅野 忠雄

出版者

日本脳神経外科学会

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

vol.22, no.6, pp.437-445, 1982-06-15

被引用文献数

8 13

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The authors reported 7 cases that showed development of new aneurysms or enlargement of small aneurysms originally less than 3mm in diameter. New aneurysms of the anterior communicating artery and the right pericallosal artery were found in one case. In this patient with a 5 year history of hypertensiovn, cerebral angiography performed 8 years before following a head trauma had revealed marked arteriosclerosis and a hypoplasia of A1_1, but no aneurysm. Development of an aneurysm from a dilatation at the origin of the right embryonal posterior cerebral artery was found 3 years after the clipping of an aneurysm of the left internal carotid artery in the other case. In 3 cases, a small unruptured aneurysm all originally less than 3mm in diameter previously noted in conjunction with a ruptured aneurysm were found to have enlarged 3 to 13 years after the clipping of the ruptured aneurysm. In these 3 cases, anomalies of the circle of Willis, such as hypoplasia of unilateral A_1, infundibular dilatation at the origin of the posterior communicating artery and the embryonal posterior cerebral artery were revealed. Arteriosclerosis and hypertension were noted in 2 cases. In 2 cases, a small ruptured aneurysm, which had not been recognized at the first subarachnoid hemorrhage, was noted to have enlarged 5 and10 years after the first bleeding. Changes of the arterial wall due to hypertension, arteriosclerosis, etc., and hemodynamic stress caused by anomalies of the circle of Willis seemed to be responsible for the new development of aneurysm and the enlargernent of aneurysm. A small aneurysm less than 3mm in diameter, including an unruptured aneurysm that is found in association with the ruptured aneurysm, have a high incidence of progressive enlargement and rupture. Therefore, even a small aneurysm should be diagnosed and treated precisely.