Abstract No. 183 Embolization of Spinal CSF Dural-Venous Fistulae for Management of Spontaneous Intracranial Hypotension

Spontaneous intracranial hypotension (SIH) is characterized by CSF hypovolemia resulting in a variety of symptoms which are dominated by chronic orthostatic headache. SIH is caused by a dural defect leading to a CSF leak or by a CSF dural-venous fistula, a pathologic connection between the CSF-containing spinal nerve root sleeve and an adjacent radicular vein. The purpose of this study was to report our early experience with transvenous embolization of spinal CSF dural-venous fistulae for management of SIH. Over a 14-month period (August 5, 2021 to September 28, 2022), 30 patients with symptoms of SIH and a confirmed CSF dural-venous fistula on CT myelography were referred for transvenous fistula embolization. Using a common femoral vein approach, a balloon occlusion microcatheter was advanced into the target segmental vein and inflated to allow retrograde injection of Onyx-18 into the associated radicular vein until there was filling of the epidural veins. Medical records were retrospectively reviewed with a mean follow-up duration of 6.9 months. Prior to intervention, the majority (87%) of patients had orthostatic headache; other common symptoms included disequilibrium, neck pain, tinnitus, fatigue, and difficulty concentrating. Symptoms were present for 1-21 years and patients had undergone 1-12 prior blood patch procedures but with symptom recurrence. All patients had persistent brain MRI findings characteristic of SIH including brain sagging and pachymeningeal enhancement. 93% of treated fistulas were located in the thoracic spine. Technical success was achieved in 97% of cases. Twenty-three patients (77%) reported significant improvement in symptoms after embolization, with 13 patients (45%) reporting complete resolution of symptoms. Post-procedure, 15 patients (52%) had symptoms of moderate to severe rebound intracranial hypertension warranting acetazolamide; however, only 1 patient required a lumbar puncture for CSF decompression. Follow-up brain MRI was obtained in 24 patients at a mean of 82 days post procedure, with 67% showing improvement or resolution of abnormalities, which correlated with symptom improvement. There were no procedural complications. Balloon-occluded retrograde transvenous embolization of spinal CSF dural-venous fistulae is a safe and effective procedure, resulting in substantial clinical improvement in the majority of patients. Additional studies are needed to assess durability of clinical response and to further define patient selection criteria.