Spinal dural arteriovenous fistulas supplied by branches of the internal iliac arteries.

Spinal dural arteriovenous fistulas are abnormal arteriovenous connections on the surface of the dura. They are supplied by branches of intercostal, lumbar, vertebral, middle sacral, or subclavian arteries and rarely by branches of the internal iliac arteries. We present four cases of spinal dural arteriovenous fistulas supplied exclusively by branches of the internal iliac artery in which the clinical and magnetic resonance presentation were not suggestive of this unusual supply. In our experience, internal iliac artery supply was observed in 12.5% of cases of spinal dural arteriovenous fistulas. We recommend that selective internal iliac arteriography be included in the angiographic evaluation of patients suspected of having a spinal dural arteriovenous fistula.