title: Lumbar extradural arteriovenous malformation: case report and literature review.
abstract: BACKGROUND
  Most spinal arteriovenous malformations (AVMs) are dural arteriovenous fistulas in which a singularly intradural venous drainage emanates from an extradural nidus. A pure extradural spinal arteriovenous malformation (E-AVM), in the absence of a vertebral body (cavernous) hemangioma, is extremely rare, and full clinical, radiological, and operative descriptions are scant.
  
  
  OBJECTIVE
  To fully document the rare occurrence of a symptomatic E-AVM producing spinal claudication.
  
  
  METHODS
  Case report.
  
  
  METHODS
  One patient.
  
  
  METHODS
  Radiological and functional.
  
  
  METHODS
  This 62-year-old man presented with 6-month progressive spinal claudication, leg weakness, and diminished sensation. Electromyography revealed bilateral acute and chronic partial degeneration of L3-S1 nerve roots. Magnetic resonance imaging revealed moderate canal stenosis between L2-L4, with prominent epidural veins on the left at L3-L4. Spinal angiography was unsuccessful, and computed tomographic myelography merely confirmed minimal lumbosacral root filling. At decompressive L2-L4 laminectomy, inadvertent hemorrhage from varicose epidural veins released arterialized blood under considerable pressure. Only minor clinical improvement was noted after this procedure. Spinal angiography 6 weeks later subsequently confirmed an E-AVM on the left at L3-L4 which was successfully embolized.
  
  
  RESULTS
  Follow-up at 8 weeks after this procedure confirmed significantly increased walking distance, improved distal sensation, and normal power in both legs, with insignificant claudication.
  
  
  CONCLUSIONS
  When associated with canal stenosis, E-AVMs may exacerbate claudication by both compressive and venous-hypertensive mechanisms. Treatment should be by embolization, with laminectomy deferred.
authors.affiliation: Department of Neurosurgery, Oldchurch Hospital, Waterloo Rd, Romford, Essex RM7 0BE, UK. l.a.g.marshman@btinternet.com
authors.forename: Laurence A G
authors.initials: LA
authors.lastname: Marshman
authors.forename: Karoly M
authors.initials: KM
authors.lastname: David
authors.forename: Sanjiv J
authors.initials: SJ
authors.lastname: Chawda
mesh_terms: D000792:Angiography; D001165:Arteriovenous Malformations / Q000601:surgery*; D020785:Central Nervous System Vascular Malformations / Q000601:surgery*; D006801:Humans; D008159:Lumbar Vertebrae / Q000098:blood supply*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged