Arteriovenous fistulae of the meninges draining into the spinal veins

The histological study of 28 cases of arteriovenous fistulae of the meninges draining into spinal veins, previously known as retromedullary arteriovenous malformations, has shown that the shunt is located inside the thickness of the dura mater. It is fed by a normal artery and drains through a single and abnormal vein. Our histological documents lead us to the conclusion that this entity is not a genuine arteriovenous malformation but, in all probability, an aquired lesion.