脳神経外科速報

Abstract

Introduction: Spinal arteriovenous malformations (AVMs) are classified into 3 types, intramedullary AVM, perimedullary arteriovenous fistula (AVF) and dural AVF. They usually present with subarachnoid hemorrhage or intramedullary hemorrhage or congestive myelopathy. Especially at the cervical level, the classification of AVMs is not enough because of its complicated vessel anatomy. Recently, a concept of radicular AVF that has shunting point inside of dura near root sleeve separate from spinal cord surface is advocated. Here, we report a case of cervical radicular AVF presenting with subarachnoid hemorrhage treated by endovascular therapy and direct surgery. Case presentation: 60 years old female presented sudden onset of severe headache and was admitted to our hospital. Computed Tomography (CT) showed subarachnoid hemorrhage but no intracranial aneurysm was confirmed. Left vertebral artery (VA) angiography showed intradural AVF fed by from left C5 radiculomedullary artery through anterior spinal artery and vasa corona. The fistula drained into right C4 radicular vein and aneurysm was found at C3 level of the proximal feeder. Right VA angiography showed epidural AVFs around the paravertebral venous plexus at C4, C5 and C6 level. Coil embolization to the aneurysm was tried but only feeder occlusion was performed because of difficulty of guiding micro catheter. So later, aneur ysmectomy with C3 and C4 corpectomy and anterior cervical fusion by direct surgery was performed on 10th hospital day. Postoperative course was good and the patient discharged on 22nd hospital day without neurological deficits. Postoperative angiography showed disappearance of intradural fistula and aneurysm, but multiple epidural fistulas around paravertebral venous plexus were remained. Conclusion: We considered that most appropriate AVF classification of this case is ‘radicular AVF’. This concept is different from dural AVF in the point of that feeding arteries are intradural pial vessels, and also different from perimedullary AVF in the point of that shunting points were found near the root sleeve separate from spinal cord surface. The interesting point of this case is coexistence of intradural fistula near the root sleeve and epidural fistulas in multiple vertebral levels. This feature can be recognized a type of SAMS (Spinal Arteriovenous Metameric Syndrome) that has anormaly of vascular, cutaneous, muscular, osseous and medullary lesions at the same metamere or spinal segment.