Transvenous Embolization of Intracranial Dural Arteriovenous Shunts through Occluded Venous Segments: Experience in 51 Patients

Dural AVF with incomplete occlusion following transvenous therapy. A 66-year-old woman presented with proptosis and chemosis of the right eye with mild diplopia. A and B, Cerebral angiogram reveals a caroticocavernous DAVF at the right cavernous sinus with arterial supply from the meningohypophyseal trunk (A) and meningeal branches from the ECA (B), with cortical venous reflux toward the posterior fossa and nonvisualization of the right IPV. With the previously described transvenous reopening technique, a microcatheter is advanced into the cavernous sinus. C, Microcatheter injections reveal the cortical venous reflux. The position of the microcatheter is deemed sufficient for subsequent coil embolization with the aim of first occluding the potential cortical venous reflux toward the posterior fossa. During deployment of the first coil, the microcatheter was pushed back, and access to the posteriorly directed venous outlet toward the posterior fossa was lost. Because access to this outlet could not be regained immediately, it was erroneously deemed sufficient to perform a dense packing of the cavernous sinus to obliterate the shunt. D, While ECA control injections (used during the coiling procedure to control for obliteration of venous reflux) showed obliteration of the DAVF, the final control injection into the ICA, however, still demonstrated reflux to the posterior fossa; and despite multiple attempts, it was not possible to regain access to the vein responsible for the cortical venous reflux, given the coil mass deposited into the sinus. Therefore, surgical disconnection of the remaining cortical venous reflux was deemed necessary. E, During surgical exposure of the cavernous sinus region, the posteriorly directed vein from the cavernous sinus that was responsible for the residual shunt is detected and the vein is coagulated. F, Follow-up angiogram after surgery demonstrates obliteration of the cortical venous reflux. This case demonstrates that it is always necessary to disconnect the cortical venous reflux before obliterating the venous sinus because packing of the sinus may preclude subsequent catheterization of cortical venous outflow tracks. This case also demonstrates that if cortical venous reflux is demonstrated to arise from multiple vessels (in this case both the ICA and the ECA), arterial control injections should be performed in both vessels to verify obliteration of the cortical venous reflux.