Spontaneous arteriovenous fistula of the orbit: case report

BACKGROUND: A spontaneous arteriovenous fistula of the orbit is exceedingly rare. We report the first case of such condition treated with direct surgical exposure of the superior ophthalmic vein (SOV) followed by embolization. CASE DESCRIPTION: A 55-year-old man presented with upper lid swelling, conjunctival chemosis, and proptosis of the right eye. Angiography revealed an intraorbital shunt supplied by the ophthalmic artery whose venous drainage curved anteriorly to the SOV. Because transarterial and transvenous endovascular approaches to treat the fistula were impossible, we performed direct surgical exposure of the SOV followed by the embolization of the fistula. Postoperative angiograms demonstrated complete closure of the fistula. All symptoms had disappeared by 2 months after surgery. CONCLUSIONS: For appropriate treatment planning, it is necessary to identify the location of the shunt. In cases where transarterial and transvenous endovascular approaches to treat the fistula are difficult or impossible, direct surgical exposure of the SOV followed by embolization may accomplish complete closure of the fistula without significant risk for iatrogenic injury.