Onyx is associated with poor venous penetration in the treatment of spinal dural arteriovenous fistulas.
OBJECTIVE
The use of Onyx has become the mainstream for the treatment of cranial dural arteriovenous fistulas (AVFs) and arteriovenous malformations, but the reported success for type I spinal dural arteriovenous fistulas (sDAVFs) remains limited. We review our experience with Onyx and report its limitations in the treatment of spinal AVFs.


METHODS
We retrospectively reviewed the Interventional Neuroradiology Procedure database at Washington University for cases of sDAVF embolization. Radiology reports were reviewed for fistula classification, treatment technique, and initial and follow-up results. Angiographic images were reviewed to confirm diagnosis, treatment, and penetration of embolisate into the draining vein.


RESULTS
With the use of Onyx, sDAVFs were obliterated in six of seven patients at the time of treatment. Follow-up angiography confirmed sDAVF obliteration in two patients, and recurrence in two cases. Two patients had no follow-up. One patient not cured at the time of treatment was treated surgically. Of the nine total treatments, Onyx successfully crossed the nidus into the draining vein in only four cases. Successful venous embolization was facilitated with positioning of the microcatheter to less than 5 mm from the nidus in three of the four cases. The use of n-butyl cyanoacrylate (NBCA) resulted in venous penetration in eight of 10 cases, and short term follow-up cure in seven of 10 patients.


CONCLUSIONS
Our experience with Onyx for type I sDAVF embolization has been tempered by difficulty in achieving venous penetration and, consequently, a high rate of recurrence. For management of these fistulas, we favor NBCA or surgical treatment.
Department of Neurosurgery, University of Florida, Gainesville, Florida, USA.
Spiros L
SL
Blackburn
Interventional Neuroradiology, Abbott Northwestern Hospital, Minneapolis, Minnesota, USA.
Yasha
Y
Kadkhodayan
Department of Neurosurgery, Washington University School of Medicine, St Louis, Missouri, USA.
Wilson Z
WZ
Ray
Department of Neurosurgery, Washington University School of Medicine, St Louis, Missouri, USA.
Gregory J
GJ
Zipfel
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri, USA.
DeWitte T
DT
Cross
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri, USA.
Christopher J
CJ
Moran
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri, USA.
Colin P
CP
Derdeyn
D000368:Aged; D020785:Central Nervous System Vascular Malformations / Q000150:complications* / Q000473:pathology / Q000628:therapy*; D004338:Drug Combinations; D004388:Dura Mater / Q000473:pathology; D004621:Embolization, Therapeutic / Q000379:methods*; D004659:Enbucrilate; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011145:Polyvinyls; D012008:Recurrence; D012189:Retrospective Studies; D013635:Tantalum; D016896:Treatment Outcome; D014680:Veins / Q000473:pathology*
D004338:Drug Combinations; C558446:Onyx 18; D011145:Polyvinyls; D013635:Tantalum; D004659:Enbucrilate
Catheter; Embolic; Fistula; Spine; Vein