経時的変化が確認できた解離性中大脳動脈瘤の1例  [in Japanese] Dissecting Aneurysm of the Middle Cerebral Artery Growing During Long-term Follow-up: A Case Report  [in Japanese]

頭蓋内解離性動脈瘤は椎骨脳底動脈系に多く, 内頸動脈系に少ないと報告されている. 紡錘状動脈瘤, 解離性動脈瘤という用語は病態, 形態学的所見が同じ土俵で議論され概念が曖昧である. 近年, Mizutaniは, giant fusiform aneurysm, megadolichobasilar aneurysm, giant serpentine aneurysmと呼ばれている脳動脈瘤も, 脳動脈解離を原因として巨大動脈瘤になるという概念を提唱している. 今回われわれは経時的観察により中大脳動脈狭窄症より紡錘状動脈瘤への変化が確認できた症例を経験した. 紡錘状動脈瘤の成因を考えるうえで示唆に富む症例であり報告する. 症例 症例:54歳, 女性. 既往歴:高血圧, 高脂血症. 家族歴:特記すべきことなし. 現病歴:1993年1月28日, 頭重感, 右片麻痺が出現し当科に入院した. 脳梗塞, 左中大脳動脈狭窄と診断し, 保存的加療を行った. 右片麻痺は数日で改善し, 以後神経脱落症状なく外来通院していた. 頭部MRA上, 同部位に紡錘状の動脈瘤が疑われたため, 2002年10月29日入院となった.

The term "fusiform aneurysm" often causes confusion because it, is sometimes wrongly used synonymously with the term "dissecting aneurysm." We report a rare case of dissecting aneurysm in the left middle cerebral artery (MCA). A 45-year-old woman was admitted to our hospital with right hemiparesis on January 28, 1993. CT showed an infarct in the territory of the perforating branch of the M1 segment. Carotid angiogram showed a linear stenosis in the M1 distal portion. The patient was treated conservatively, and remained neurologically stable for 9 years following initial presentation, but serial magnetic resonance angiography (MRA) revealed growth of the aneurysm. Carotid angiogram showed a fusiform aneurysm of the M1-2 portion. The patient, underwent surgery by left pterional approach on November 11, 2002. The wall was yellow, firm, and arteriosclerotic. Finally, it was coated with Bemsheet soaked in Biobond. The postoperative course was uneventful. We suggest that in the present case of fusiform aneurysm, the pathogenesis is dissection. Careful interpretation of serial angiograms and magnetic resonance images will be necessary for a long time because the disease may progress. If the aneurysmal size increases, surgery must be evaluated.