Fig 6.

Right sigmoid sinus DAVFs (type IIa) with a localized shunted venous pouch at the proximal horizontal portion of the sigmoid sinus. A–C, Frontal and lateral views of selective angiography of the right ascending pharyngeal artery and lateral view of the left external carotid angiography show the DAVF involving the sigmoid sinus. The DAVFs are mainly fed by the ascending pharyngeal artery and the occipital artery and drain retrogradely via the transverse-sigmoid sinus into the superior sagittal sinus due to the occlusion of the right jugular vein. D, Axial reformatted images of rotational angiography of the right external carotid artery show a shunted pouch (asterisk) that is located inferomedially to the proximal horizontal portion of the sigmoid sinus. The shunted pouch was fed by a hypoglossal branch (HGB) and a jugular branch (JB) of the ascending pharyngeal artery and by a stylomastoid branch (SMB) and transosseous branches (TOB) of the occipital artery (OA). E, Right common carotid angiography after selective transvenous embolization of the shunted pouch shows the disappearance of the DAVFs.