Fig 3.

Left transverse sigmoid DAVFs (type IIa) with 3 shunted venous pouches. Frontal (A) and lateral (B) views of the left external carotid angiography show DAVFs involving the left transverse-sigmoid sinuses. The DAVFs are fed by multiple branches of the external carotid artery and drain into the posterior condylar vein, the mastoid emissary vein, and the superior petrosal sinus with occlusion of the sigmoid sinus at the proximal end. Frontal view of right vertebral angiography (C) shows the DAVF fed by the posterior meningeal artery. D, Axial reformatted images of rotational angiography of the left external carotid artery show 3 shunted pouches, which are located dorsal to the vertical portion of the sigmoid sinus (SP1), at the transverse sigmoid junction (SP2), and inferior to the distal transverse sinus (SP3). The SP1, SP2, and SP3 are fed by the jugular branch (JB) and hypoglossal branch (HGB) of the ascending pharyngeal artery, the petrosquamous branch (PSB) of the middle meningeal artery, and the posterior convexity branches of the middle meningeal artery and the transosseous branches of the occipital artery, respectively. E, An axial reformatted image of rotational angiography of the right vertebral artery shows the posterior meningeal artery (PMA) also supplying the shunted pouch inferior to the distal portion of the transverse sinus (SP3). F, Selective venography of the shunted pouch (SP3) via a microcatheter (arrow) selectively introduced into the SP3 shows the separated venous pouch parallel to the transverse sinus. The shunted pouch was embolized with coils. G, Selective angiography with simultaneous injection via 2 microcatheters, one positioned at the petrosquamous branch of the middle meningeal artery and the other positioned at another shunted pouch of SP2, shows a shunted venous pouch at the transverse-sigmoid junction. The shunted pouch was also embolized with coils and glue. H, Lateral view of the right external carotid angiography after embolization shows marked regression of the DAVFs. A small part of the DAVFs remains with a shunted venous pouch (arrows) located dorsal to the sigmoid sinus (SP1), which was supplied by a hypoglossal branch (HGB) and a JB of the ascending pharyngeal artery. I, Right vertebral angiography during the venous phase shows coils placed parallel to the transverse sinus. Normal sinus flow of the transverse-sigmoid sinuses is preserved.