Lumbosacral extradural spinal arteriovenous malformation with blood supply from branches of internal iliac arteries.

A case of extradural spinal arteriovenous malformation (AVM) is described. The feeding arteries were branches from both internal iliac arteries. The pre-operative diagnosis was confirmed by myelography, selective angiography and plain and enhanced CT. The AVM was demonstrated in the ventrolateral epidural space by CT scan, providing an excellent pre-operative localisation related to dural sac and nerve roots. The clinical signs and symptoms are considered to originate from the venous congestion due to the high venous pressure caused by the AV shunt. The possible predisposing factors are also briefly discussed.