Single-Session Curative Transarterial Onyx Embolization of a Convexity Dural AVF with a Concomitant Pial AVF Sharing the Vein of Labbé: A Case Report and Literature Review.

OBJECTIVE: Pial arteriovenous fistula (PAVF) is a relatively rare and most commonly congenital intracranial arteriovenous shunt. We describe a presumed acquired PAVF coexisting with a convexity dural arteriovenous fistula (DAVF) that shares a common draining vein and discuss the potential pathophysiological mechanisms with reference to the literature.

CASE PRESENTATION: A 68-year-old man presented with slowed thought. Imaging demonstrated a convexity DAVF supplied by branches of the right external carotid artery and draining into the dorsal segment of the right vein of Labbé, as well as a PAVF supplied by cortical branches of the right middle cerebral artery with ventral drainage into the same vein. Under general anesthesia, transarterial Onyx (Medtronic, Minneapolis, MN, USA) embolization via the right middle meningeal artery achieved complete occlusion of both lesions by controlled Onyx penetration within the draining vein from the dorsal to the ventral segments. Complete obliteration was achieved when the Onyx reached the pial-feeder inflow site, and the procedure was completed without perioperative complications.

CONCLUSION: Although rare, DAVF may coexist with a presumably acquired PAVF and share a common draining vein. Thorough preoperative delineation of the angioarchitecture is essential, because incomplete occlusion can precipitate delayed hemorrhage. When attempting a single-session treatment, meticulous control of Onyx reflux, avoiding inadvertent penetration into pial feeders, is critical to minimize the risk of cerebral infarction.