前脊髄動脈動脈瘤破裂によるくも膜下出血にて発症した頚髄硬膜動静脈瘻の1例

A Case of Cervical Spinal Dural Arteriovenous Fistula with Extradural Drainage Presenting with Subarachnoid Hemorrhage due to a Ruptured Anterior Spinal Artery Aneurysm

Ⅰ．はじめに

　一般に，脊髄硬膜動静脈瘻（spinal dural arteriovenous fistula：spinal dural AVF）は稀な疾患で，脊髄症状で発症することが多い²⁾．しかし，頭蓋頚椎移行部のspinal dural AVFはくも膜下出血（subarachnoid hemorrhage：SAH）で発症する割合が34〜50%^11,18)と多い．今回われわれは，SAHで発症し，頚髄spinal dural AVFを認め，前脊髄動脈動脈瘤から出血した稀な症例を経験した．また，本症例のspinal dural AVFは前脊髄動脈からの血流を受け，流出静脈は硬膜外にのみ存在した．本症例を文献的考察を加え報告する．

　We report a rare case of a cervical spinal dural arteriovenous fistula（AVF）at the C2 level presenting with subarachnoid hemorrhage（SAH）due to a ruptured anterior spinal artery aneurysm. A 61-year-old man presented with sudden onset headache. Initial computed tomography revealed SAH around the brainstem. Digital subtraction angiography（DSA）demonstrated a cervical dural AVF that was fed by the left C1 radicular, left C2 radicular, and anterior spinal arteries, and drained into the epidural plexus. An aneurysm in the branch of the cervical anterior spinal artery was considered the bleeding point. A left lateral suboccipital craniotomy and C1 hemilaminectomy were performed on day 43. The feeding arteries were clipped, followed by coagulation of the draining veins. However, the aneurysm was not clipped because we deemed that obliteration of the aneurysm would be difficult without disrupting the blood flow of the parent artery. The patient showed no neurological deterioration after the operation. Postoperative DSA revealed residual dural AVF. Therefore, a second surgery was performed. After the second open surgery, DSA showed that the dural AVF and aneurysm disappeared. The patient also showed no neurological deterioration after the second surgery.