Intraorbital Dural Arteriovenous Fistula Treated by Transarterial Embolization Using Onyx: A Case Report

Objective: Intraorbital dural arteriovenous fistula (IO-dAVF) is a rare condition, and treatment options vary from case to case. We report a case of transarterial embolization (TAE) for IO-dAVF. Case Presentation: A 62-year-old male complained of gradually worsening pain, hyperemia, and visual impairment in the right eye. He did not exhibit diplopia or exophthalmos. Cerebral angiography revealed an arteriovenous fistula in the right orbit. The feeding arteries were the ophthalmic artery (OphA) and the artery of the superior orbital fissure (ASOF), with the superior ophthalmic vein (SOV) as the main draining vein. The venous pathway from the SOV was not clearly visible, and considering the risk of blindness with TAE from the OphA, TAE from the ASOF was performed. Onyx 18 was selected as the liquid embolic material and injected through a microcatheter placed in the internal maxillary artery. Occlusion up to the SOV was achieved, and the shunt flow completely disappeared. Normal blood flow in the OphA was maintained, hyperemia improved, and no complications were observed. Conclusion: In cases of IO-dAVF, when transvenous embolization is difficult to perform, TAE using Onyx from the vessel of the external carotid artery system may be preferred over OphA.