Technical video: Onyx-18 embolization of spinal epidural arteriovenous Fistula using the scepter-Mini balloon catheter.

Spinal arteriovenous fistulas (AVFs) account for approximately 70% of all vascular spinal malformations and commonly develop in the lateral epidural space at the epidural /radicular venous junction. The fistula is located close to the spinal nerve root where a radiculomeningeal artery shunts to a radicular vein. Increased venous pressure leads to decreased spinal venous drainage and venous congestion causing progressive myelopathy, bowel/bladder incontinence and erectile dysfunction. Treatment consists of surgical occlusion of the intradural vein, or endovascular embolization, which has a reported success rate of 25%-75%.¹ Endovascular failure can occur with inadequate embolic penetration of the nidus and the proximal segment of the draining vein, or premature reflux of the liquid embolic agent.The use of a dual-lumen balloon microcatheter offers advantage in these cases given the ability to push liquid embolysate more distally during balloon inflation. The Scepter Mini is a new dimethyl-sulfoxide (DMSO)-compatible dual-lumen balloon microcatheter with a distal-tip outer diameter of 1.6 Fr and a nominal balloon diameter of 2.2 mm, facilitating atraumatic navigation and safer balloon inflation. Limited neurointerventional experience using the Scepter Mini in predominantly cerebrovascular cases has reported favorable navigability and flow arrest^{2, 3} Although Onyx is rarely used for spinal AVF embolization, success has been reported considering the well-known favorable experience in cerebral cases.^{1, 4, 5}We present one of the first cases of Onyx embolization of a spinal dural AVF through a Scepter Mini in a patient with progressively worsening lower extremity sensorimotor dysfunction. Operators should be aware of radiculomedullary arteries arising at the same level or at adjacent levels to avoid unintentional Onyx migration during balloon inflation.