Multimodal Treatment of Occipital Tentorial Dural Arteriovenous Fistula Cognard III.

Dural arteriovenous fistulas (dAVFs) are rare vascular malformations of uncertain pathophysiology. If associated with cortical venous reflux, they present a significant risk of hemorrhage. We present a 69-year-old patient who presented with spontaneous right-sided symptomatic chronic subdural hematoma, which was evacuated via burr hole. Due to lack of history of prior trauma, computer tomography angiography was performed, which showed dilated convoluted vessels in the right occipital region and an enlarged right posterior cerebral artery, suspected to be an arteriovenous malformation or dAVF. Subsequent angiography demonstrated occipital tentorial dAVF with primary cortical venous reflux (Cognard III) and reflux into the transverse sinus, fed primarily from the petrosquamous branch of the middle meningeal artery and neuromeningeal trunk. The fistula was initially treated by transarterial endovascular embolization of the occipital artery and neuromeningeal trunk with Onyx, achieving complete obliteration. However, follow-up angiography demonstrated recurrence of the lesion fed from the contralateral middle meningeal artery and pial branches of the enlarged right posterior cerebral artery. Given the recruitment of the contralateral supply from the left middle meningeal artery and ipsilateral posterior cerebral artery, we felt that surgical disconnection of the fistula was the best option for the patient. An occipital craniotomy with disconnection of the fistula without isolation of the transverse sinus was performed (Video 1), as published literature demonstrated lower intraoperative risk with disconnection only. The perioperative course was uneventful. Immediate postoperative and follow-up angiography demonstrated complete occlusion of the fistula.