Does this confirm the diagnosis of a spinal arteriovenous fistula? Anything unusual?
Yes, but in this case there are two fistulas, one from the 3rd intercostal and a second form the 6th.
What proportion of spinal dural AV fistulas have more than one fistulous location?
The majority are single (85%) and consist of a single transdural arterial feeder, however in the remainder there may be many arterial feeders originating from either a single or multiple levels that may be either unilateral or bilateral
Look at the angiogram carefully and identify the following: 1) intercostal artery 2) site of fistula and 3) distended perimedullary veins.
See the following annotated images.
What are the treatment options?
Treatment options include endovascular or surgical occlusion of the shunt. Endovascular occlusion: performed with either glue or N-butyl-2-cyanoacrylate (Onyx) after superselective catheterization of the radiculomeningeal artery supplying the fistula. Surgical occlusion consists of a targeted laminectomy and intradural exploration with coagulation or disconnection of the draining vein.
There are two areas of arteriovenous shunting filling from nerve root sheath to perimedullary veins.
A common trunk supplies the third and fourth intercostal arteries. The highest fistula is from the right third intercostal. The drainage from this level was into tortuous perimedullary veins around the cervical and upper thoracic cord.
A second separate lower fistula filled from a right sixth intercostal branch, with drainage being preferentially inferiorly into distended perimedullary veins; these account for the flow voids seen on the initial MRI.