Microsurgical treatment of a posterior fossa arteriovenous malformation initially mistaken for a dural arteriovenous fistula: avoidance of near disaster.

Many brain arteriovenous malformations (AVMs) derive dural blood supply, while 10%-15% of dural arteriovenous fistulas (dAVFs) have pial arterial input. To differentiate between the two is critical, as treatment of these entities is diametrically opposed. To treat dAVFs, the draining vein(s) is disconnected from feeding arteries, which portends hemorrhagic complications for AVMs. The authors present an operative video of a subtle cerebellar AVM initially treated as a dAVF by attempted embolization through dural vessels. The lesion was subsequently microsurgically extirpated. The authors show a comparison case of an AVM mistaken for a dAVF and transvenous embolization that resulted in a fatal hemorrhage. The video can be found here: https://youtu.be/eDeiMrGoE0Q.