Difficult cannulation of the superior ophthalmic vein in the treatment of cavernous sinus dural arteriovenous fistula: two case reports

Retrograde cannulation of the superior ophthalmic vein (SOV) is an important route for embolization of cavernous sinus dural arteriovenous fistula (dAVF). We encountered two cases with significant difficulties with cannulation of the SOV. A 66-year-old woman and an 83-year-old woman were referred to our hospital for treatment of cavernous sinus dAVF. Unilateral chemosis and exophthalmos were seen in both patients. At first, transarterial embolization was performed to reduce the flow, then, transvenous embolization was employed for the treatment of cavernous sinus dAVF. The attempts to embolize through a transfemoral route failed owing to a thrombosed or compartmentalized cavernous sinus. Surgical exposure of the SOV and puncture with needle-cannula was tried. However, in both cases, unsuccessful cannulation resulted in uncontrollable bleeding and periorbital swelling. Finally, by using road-mapping SOV was punctured in the deeper part and the fistula was obliterated with detachable coils. Postoperative course was uneventful and their symptoms were improved. Although the SOV is a useful route for cavernous sinus dAVF embolization, the presence of narrowed or tortuous veins can preclude successful cannulation.