脳静脈洞血栓症を認めた21カ月後に新たに発生した硬膜動静脈瘻の1例

A Case of Dural Arteriovenous Fistula that Developed 21 Months after Cerebral Venous Sinus Thrombosis

Ⅰ．はじめに

　成人に発生する硬膜動静脈瘻（dural arteriovenous fistula：dAVF）の多くは，静脈性高血圧によって後天的に引き起こされると考えられているが^2,13)，実際に静脈の閉塞性変化が先行してdAVFの発生を認めることは多くない．今回われわれは，脳静脈洞血栓症（cerebral venous sinus thrombosis：CVST）による脳出血の後に経過観察を行っていたところ，新たに発生したdAVFによる脳出血を発症した症例を経験したので報告する．

　A 56-year-old man experienced a sudden onset of left hemiparesis. The computed tomography（CT）scan revealed a lobar hemorrhage in the right fronto-parietal lobe. After his admission, deep vein thrombosis was detected in his left lower limb, and angiograms taken on the 36th day of hospitalization revealed cerebral venous sinus thrombosis. Anticoagulant treatment was induced. After 21 months, he experienced a sudden onset of left hemiparesis again. The CT scan revealed a new lobar hemorrhage in the right frontal lobe, and angiograms revealed that two dural arteriovenous fistulas（dAVF）developed in the superior sagittal sinus（SSS）and the left transverse-sigmoid sinus. The one in the SSS had retrograde drainage from the bilateral middle meningeal artery, and we performed transarterial embolization with 50% n-butyl-cyanoacrylate. Postoperative course was uneventful and no further stroke occurred.

　Intracranial dAVF is known to be an acquired disease caused by venous hypertension, but we rarely find new development of dAVFs after venous diseases. This patient's case will help to elucidate the pathophysiology of dAVF.