Intradural radicular arteriovenous fistula that mimics dural arteriovenous fistula: report of three cases.

We herein present three cases of a rare type of spinal AVF, an intradural radicular AVF, which mimicked a dural AVF. A 65-year-old male presented with congestive myelopathy. On angiography, right vertebral angiogram (VAG) showed a suspected dural AVF; however, left VAG showed the same intradural dilated vein fed by the anterior spinal artery (ASA). Intraoperative and histological results suggested that a single AVF was located on the right C1 nerve root fed by the right C1 radicular artery and branch of the anterior spinal artery. Two additional patients with a radicular AVF at the C3 or C5 level were presented. Intradural radicular AVFs and dural AVFs have very similar appearances; however, there is a difference that makes the risk of the endovascular treatment of radicular AVFs markedly higher because of blood supply from the ASA. In our case, the AVF was completely occluded by direct surgery without major complications.