There are two areas of arteriovenous shunting filling from nerve root sheath to perimedullary veins.
The highest flow is from the right third intercostal which arises from the supreme intercostal. Microcatheter selective assessment of this vessel as it previewed the possible Onyx or NBCA embolisation identified a spinal artery arising from the same radicular branch; embolisation was not performed. The drainage from this level was into tortuous perimedullary veins around the cervical and upper thoracic cord.
A second separate focus of spinal dural arteriovenous fistula filled from a right sixth intercostal branch, with drainage being preferentially inferiorly into distended perimedullary veins. Microcatheter assessment of this showed that the communication to the intervertebral foramen was of smaller calibre than the catheter.
This level was marked with three platinum radio-opaque microcoils (incidentally after which this level was no longer filling). This should enable fluoroscopic localisation of this level and also a cyst in identifying the right third intercostal level (which was not marked with a coil given the presence of a significant spinal artery supply from this level).
Artery of Adamkiewicz left T12 . No other significant abnormality.