Transvenous Onyx embolization of a recurrent dural arteriovenous fistula through the deep venous system.

Transarterial and, to a lesser extent, transvenous embolizations are commonly used in the treatment of cerebral dural arteriovenous fistulas (dAVFs).1 When the feeding artery is small and tortuous, leading to difficult or impossible safe navigation and effective embolization, transvenous embolization may be a safe alternative.2 3 The efficacy of transvenous strategies relies on successful navigation of the draining vein up to the arterial-venous connection of the fistula ('foot of the vein'). This strategy has been shown to be an effective way of treating otherwise inaccessible dAVFs with low morbidity and improved occlusion rates.4 We present the transvenous coil and Onyx (Medtronic, Minnesota, USA) embolization technique for a previously treated and recurrent dAVF involving tentorial feeders from the inferolateral trunk (video 1). It is a unique case in which counterflow navigation into the draining vein was achieved through the deep venous system via the right basal vein of Rosenthal, with the use of balloon intermittent flow arrest. neurintsurg;15/4/408/V1F1V1Video 1 .