Supreme Anterior Communicating Arteryを合併した両側末梢性前大脳動脈瘤の1例

Bilateral Distal Anterior Cerebral Artery Aneurysm Associated with Supreme Anterior Cerebral Artery : case report

I．はじめに

　前交通動脈より末梢に発生する脳動脈瘤は末梢性前大脳動脈瘤（distal anterior cerebral arteryaneurysm，以下DACA）とよばれ，azygos ante-rior cerebral arteryをはじめとする前大脳動脈の破格を伴うことが多い^10）．また脳動脈瘤の発生原因を考察する場合にしばしば取り上げられる特異な脳動脈瘤でもある^13,15）．一方，多発性脳動脈瘤のなかで両側対称性に存在するものに対し，Bigelowらはsymmetrical bilateral intracranialaneurysmという範疇を提唱している^3）．今回われわれは，supreme anterior communicating artery（以下SACom）^15）を伴いpericallosal arteryとcal-losomarginal artery分岐部に発生した両側対称性の末梢性前大脳動脈瘤（bilateral distal anteriorcerebral artery aneurysm，以下BDACA）を経験した．DACAのなかでもBDACAは稀と思われ，文献的考察を加えて報告する．

A 67-year-old woman presented with bilateral distal anterior cerebral artery aneurysms manifesting asconsciousness disturbance. Computed tomography revealed subarachnoid hemorrhage in the interhemi-spheric fissure, right sylvian fissure, and a hematoma in the right frontal lobe and lateral ventricles.Angiography showed bilateral symmetrical aneurysms located on the pericallosal artery at the bifurcationof the callosomarginal artery. The operation was performed on the day the patient was admitted. Theaneurysms were clipped via the interhemispheric approach, and the hematoma was aspirated. Operativeview demonstrated rupture of the left aneurysm, and supreme anterior cerebral aneurysm. Postoperativeangiography showed disappearance of the aneurysms and an intact bilateral anterior cerebral artery. Thepatient was discharged with mild organic mental syndrome. However, a few days later, she was admittedagain with a high fever and died of complications due to sepsis. Pathological view showed clippedaneurysms and the connection of the bilateral distal anterior cerebral artery with the so-called supremeanterior communicating artery.