title: The Coexistence of Extradural Arteriovenous Fistula and Soft Tissue Arteriovenous Malformation Within the Same Metamere.
abstract: BACKGROUND
  Spinal arteriovenous shunts are a common spinal vascular disorder. However, they can have a misleading clinical presentation and poor prognosis. They are classified into 4 types according to shunt points and drainage route, among which extradural arteriovenous fistula (eAVF) is the most rare, comprising only 1% of all spinal arteriovenous shunts. We report an extremely rare case of coexistent eAVF at the craniocervical junction and soft tissue arteriovenous malformation within the same metamere.
  
  
  METHODS
  A 30-year-old man presented with neck pain. T2-weighted magnetic resonance imaging revealed a flow void at the right craniocervical junction compressing the spinal cord. Angiography revealed eAVF at the craniocervical junction. The patient was treated via transvenous embolization. After the procedure, shunt flow and symptoms markedly decreased. During the operation, an extracranial arteriovenous malformation under the occipital skin was detected immediately after occluding the shunt point.
  
  
  CONCLUSIONS
  This case indicates that transvenous embolization can be an effective treatment for eAVF and supports some hypotheses of arteriovenous malformation development. Additionally, it emphasizes the importance of examining a lesion with multiple modalities, including angiography, three-dimensional angiography, and cone-beam computed tomography, to understand the anatomy of the lesion.
authors.affiliation: Department of Neurosurgery, Keio University Hospital, Tokyo, Japan. Electronic address: dobu@i.softbank.jp.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Arai
authors.affiliation: Department of Neurosurgery, Keio University Hospital, Tokyo, Japan.
authors.forename: Takenori
authors.initials: T
authors.lastname: Akiyama
authors.affiliation: Department of Neurosurgery, Keio University Hospital, Tokyo, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000328:Adult; D001164:Arteriovenous Fistula / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery*; D001165:Arteriovenous Malformations / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery*; D054893:Cone-Beam Computed Tomography; D004621:Embolization, Therapeutic; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D013116:Spinal Cord / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery
keywords: Arteriovenous fistula; Arteriovenous malformation; Metamere; Spinal extradural arteriovenous fistula; Transvenous embolization