P050 Transvenous approach to commute a complex dural arteriovenous fistula of the right transverse sinus, comprising cerebellar cortical veins drainage, to a type 1 with assistance of 3D rotational acquisitions fusion to navigate the fistulous channe

<h3>Introduction</h3> (Endovascular treatment has become the first option in the management of arteriovenous dural fistulas. It may anyway be challenging in case of complex anatomy. <h3>Case Description</h3> We present the case of a 75 y.o. man who suffered in 2011 a cerebral venous sinus thrombosis extended to the superior sagittal sinus and both transverse sinuses. He recently came to our attention after the onset and progressive worsening of ataxia and consequent falling episodes. The cerebral angiography showed a complex arteriovenous dural fistula with feeders from multiple right external artery branches draining with antegrade flow into the right transverse sinus and other feeders from left occipital and middle meningeal arteries draining partly into cortical cerebellar veins through a medial tentorial sinus and partly into the right transverse sinus (figure 1). The right transverse sinus was slightly opacified also in the venous phase during the injection thourgh the right internal carotid artery, meaning its preserved parenchimal drainage function. <h3>Results</h3> We decided for a treatment of the fistula point draining into the cerebellar cortical veins passing through the venous side (figure 2) also using the fusion of 3D rotational acquisitions as assistance to navigate the fistolous channels. We used coils to avoid less controllable reflux and to mantain the patency of the right transverse sinus. We therefore obtained the transformation of the fistula into a type 1 one interrupting the reflux into the cerebellar cortical veins (figure 3). <h3>Disclosure of Interest</h3> no.