Lumbar extradural arteriovenous malformation: case report and literature review.
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.
Marshman
Laurence A G
LA
Department of Neurosurgery, Oldchurch Hospital, Waterloo Rd, Romford, Essex RM7 0BE, UK. l.a.g.marshman@btinternet.com
David
Karoly M
KM
Chawda
Sanjiv J
SJ
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