脳動静脈奇形に合併した慢性被膜化脳内血腫が塞栓術で縮小し臨床症状改善を認めた1例

Chronic Encapsulated Intracerebral Hematoma Associated with Arteriovenous Malformation, Shrinking after Feeder Embolization with Clinical Improvement:A Case Report

Ⅰ．はじめに

　慢性被膜化脳内血腫（chronic encapsulated intracerebral hematoma：CEIH）は，血腫辺縁に被膜を形成する稀な脳内血腫である．その臨床経過は，徐々に血腫が増大し，神経症状が増悪することを特徴とし，何らかの外科的治療介入を要したとの報告が多い^{2,4-7,9,10,12-17,19,20)}．この経過は慢性硬膜下血腫（chronic subdural hematoma：CSDH）に類似し，また，CEIHの血腫被膜とCSDHの血腫外膜の病理所見には共通点が多くみられることより，病態の類似性が指摘されている^13,14)．しかし治療に関し，難治性のCSDHに対する中硬膜動脈塞栓術の有効性を示した報告は近年散見される一方，CEIHに対する塞栓術の有効性に言及した報告はない．

　今回われわれは，arteriovenous malformation（AVM）に合併したCEIHの症例を経験した．AVM摘出術のために塞栓術を行ったところCEIHが縮小する経過をたどったので，文献的考察を加え報告する．

　Chronic encapsulated intracerebral hematoma（CEIH）with arteriovenous malformation（AVM）is rare. We report a case of CEIH shrinking after feeder embolization for AVM. A 60-year-old man experiencing headaches for 2 weeks was admitted to our hospital due to intracerebral hematoma detected by MRI. The hematoma was shown as a low-density mass lesion on CT scans. Angiography and enhanced MRI showed an AVM in the right temporal lobe associated with the CEIH. Mild disturbance of consciousness and headaches gradually worsened, as the CEIH grew. Before AVM resection, feeder embolization was performed. On the day after the embolization, symptoms improved and the CEIH shrunk in size. A week following the embolization, the AVM including the partial hematoma capsule was resected without neurological deficit. Previous literature showed similarities between CEIH and chronic subdural hematoma（CSDH）in clinical features and pathological findings of the capsule. This case indicated that feeder embolization might be a treatment option for CEIH with AVM, such as embolization of middle meningeal artery for intractable CSDH.