title: Arteriovenous fistulas at the cervicomedullary junction presenting with subarachnoid hemorrhage: six case reports with special reference to the angiographic pattern of venous drainage.
abstract: OBJECTIVE
  Cases with spinal perimedullary arteriovenous fistulas (SPAVFs) or spinal dural arteriovenous fistulas (SDAVFs) at the cervicomedullary junction are rare. We performed a retrospective, angiographic study of 6 such patients to assess whether available angiographic data were predictive of the risk for hemorrhage.
  
  
  METHODS
  We report 6 patients with arteriovenous fistulas at the cervicomedullary junction. All presented with subarachnoid hemorrhage (SAH). Angiography demonstrated that 4 of the 6 fistulas were SDAVFs fed by the meningeal branch of the vertebral artery; the other 2 were SPAVFs fed by the anterior spinal artery. Drainage was via the perimedullary vein of the cervicomedullary junction.
  
  
  RESULTS
  An ascending venous route into the intracranial sinus was recognized in all 6 cases; in 3 the draining system contained varices. In 2 cases, the venous route was on the ventral side of the brain stem with drainage into the cavernous sinus. In 4 cases, the venous route was lateral at the brain stem with drainage into the inferior petrosal sinus.
  
  
  CONCLUSIONS
  SPAVFs and SDAVFs at the cervicomedullary junction that manifest an ascending venous route into the intracranial sinus present an increased risk for SAH.
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kai
authors.forename: Jun-ichiro
authors.initials: J
authors.lastname: Hamada
authors.forename: Motohiro
authors.initials: M
authors.lastname: Morioka
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Yano
authors.forename: Takamasa
authors.initials: T
authors.lastname: Mizuno
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Kuratsu
mesh_terms: D000368:Aged; D001164:Arteriovenous Fistula / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008526:Medulla Oblongata / Q000098:blood supply*; D008875:Middle Aged; D009333:Neck; D010690:Phlebography; D013116:Spinal Cord / Q000098:blood supply*; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000209:etiology*; D014680:Veins; D014711:Vertebral Artery / Q000002:abnormalities