Onyx transarterial embolization of dural arteriovenous fistula for failed N-butyl cyanoacrylate treatment: case report

Total occlusion of dural arteriovenous fistulas (DAVFs) via transarterial embolization is difficult due to the rich anastomotic network of the dural/falcine plethora of feeding arteries, blood supply to cranial nerves, and extracranial to intracranial anastomoses. Incomplete occlusion of the fistulas will result in recanalization of the DAVF from the multiple collateral arteries constituting the dural blood supply. Transvenous occlusion or surgical skeletonization of true sinus or resection of the affected venous sinus has been reported effective in selected cases. However, these treatments can be hazardous when the venous sinus drains cortical or deep veins. When total occlusion of a DAVF is difficult, surgical or endovascular selective disconnection of cortical venous reflux to control the disease is reported effective in DAVFs with combined sinus drainage and cortical venous reflux. Onyx (ev3, Irvine, CA, USA) is a new liquid embolic agent with longer precipitation time enabling prolonged injection time, with potential of better penetration into a fistulous network. Previous reports have described initial successful transarterial Onyx embolization of DAVF as a primary treatment. In our report, we present successful Onyx DAVF embolization in recurrent DAVFs previously treated with N-butyl cyanoacrylate (NBCA). Focus is given on the technique and anatomical considerations of transarterial DAVF Onyx embolization based on intraprocedural findings.