Spinal dural AVF
Anterograde outflow to spinoradicular (dural) vein or extradural venous plexus (Batson's). Benign course.
Retrograde outflow to extradural venous plexus and pial venous plexus. Show hemorrhage or progressive neurological deficit.
Retrograde outflow to pial venous plexus only. Show hemorrhage or progressive neurological deficit. Compares to DiChiro type I.