Transvenous coil embolization of an intraorbital arteriovenous fistula: Case report and review of the literature

BACKGROUND AND IMPORTANCE:: Purely intraorbital arteriovenous fistulas (AVFs), which are rare vascular malformations that clinically mimic carotid-cavernous fistulas (CCFs), involve a fistula from the ophthalmic artery to 1 of the draining ophthalmic veins. We describe a case of an intraorbital AVF treated with transvenous endovascular coil embolization via the inferior petrosal sinus (IPS) route and review the literature on this rare entity. CLINICAL PRESENTATION:: An 81-year-old woman sought treatment after 7 days of progressive left-sided visual acuity loss, chemosis, and lateral rectus palsy. Magnetic resonance imaging demonstrated dilated vascularity in the left orbit raising suspicions for a CCF. Cerebral angiography showed a purely intraorbital AVF with a fistula between the left ophthalmic artery and superior ophthalmic vein (SOV). Transvenous selective catheterization of the fistula was performed by successfully navigating the ipsilateral IPS to the cavernous sinus and SOV. The fistula was then embolized using detachable coils. The patient was discharged the next day. Three weeks after embolization, her ocular symptoms and findings had resolved. CONCLUSION:: Intraorbital AVFs are a rare type of AVF that can be treated by direct surgical ligation, transarterial embolization, or transvenous embolization. We successfully navigated the IPS, which is frequently stenotic or occluded secondary to chronically increased fistulous drainage, and utilized this route to embolize the fistula with detachable coils.