A 71-year-old woman presented with headache and dilated vessels on CTA. Angiography demonstrated a complex dural arteriovenous fistula with retrograde cortical venous hypertension, supplied by branches of internal and external carotids bilaterally into a fistulous pouch paralleling the left transverse and sigmoid sinuses, which was occluded at the jugular bulb. The patient refused treatment and was lost to follow-up, returning with sudden confusion and hemianopsia from left temporo-occipital hemorrhage. Transvenous endovascular embolization was performed using the dual-microcatheter technique with a combination of coiling and Onyx copolymer, completely occluding the sinus and fistula while preserving normal venous drainage. The video can be found here: http://youtu.be/u_4Oc7tSmDM .
Keywords: Onyx; arteriovenous fistula; embolization; endovascular; video.