Introduction and purpose Surgical disruption has been the traditional method for treatment of spinal dural fistulae. Currently the natural history of spinal dural fistula is not clearly understood. There are a few case series reported in the literature documenting successful endovascular treatment of spinal dural fistula with n-butyl cyanoacrylate (n-BCA) liquid embolic material. A relatively new liquid embolic agent ethylene vinyl alcohol (Onyx) has been used extensively in the endovascular treatment of cerebral arteriovenous malformation and dural arteriovenous fistula. The first application of Onyx in the endovascular treatment of a spinal dural fistula was reported in the literature in 2003. An additional three cases of spinal dural fistula treated successfully with Onyx were reported in 2009. We present our experience with endovascular treatment of spinal dural fistula using n-BCA and more recently Onyx.

Materials and methods We performed a retrospective review of all spinal dural fistulae cases that were treated at our institution from February 2004 to February 2010. Patient chart review, outpatient clinic follow-up letters and imaging review formed the retrospective analysis for the identified group of patients. 14 patients were identified with a spinal dural fistula. There were nine men and five women in the cohort. The age ranged from 16 to 81 years (mean 57 years). 13 were confirmed on digital subtraction spinal angiography (DSA) and one was negative on DSA.

Results 14 cases of spinal dural fistulae were treated. Three cases had to undergo surgical disruption due to the proximity of the anterior spinal artery to the arterial feeder to the fistula. All surgical cases were marked with coils in the anterior division of the intercostal artery to facilitate level identification. The 11 patients treated by endovascular embolization had a total of 14 procedures. Onyx was used as the liquid embolic agent in four cases while seven endovascular embolizations were performed utilizing n-BCA and coils. There were no procedure related complications associated with endovascular treatment. The mean follow-up of the cohort was 15 months (range 10 days–52 months). Nine of the 14 cases treated had symptomatic improvement and five were stable after treatment. All of the cases treated with Onyx had marked improvement in clinical symptoms.

Conclusion Endovascular treatment of spinal dural fistula with liquid embolic agents is safe and effective. Surgical disruption should be performed when endovascular treatment risks iatrogenic injury or is not technically possible. Onyx may be an alternative to n-BCA when encountering inaccessible arterial feeders due to anatomic tortuosity. Utilization of the unique properties of Onyx may allow the safe treatment of spinal dural fistulae from a relatively proximal location.