Figure 6c. TVE via an occluded inferior petrosal sinus with changes in the drainage pattern of a cavernous sinus dural AVF. (a) Left external carotid angiogram shows a cavernous sinus dural AVF draining mainly into the inferior petrosal sinus (arrows) and pterygopharyngeal plexus (arrowheads). (b) Follow-up angiogram obtained 3 months later shows significant changes in the drainage pattern. The inferior petrosal sinus is occluded, and the dural AVF now drains into the superior ophthalmic vein (arrows) and the superficial middle cerebral vein (arrowheads). Although the patient’s symptoms (mild chemosis, proptosis, diplopia) were unchanged during follow-up, occlusion of the dural AVF was indicated because of the change into a dangerous drainage pattern. (c) Superselective venogram shows the tip of a microcatheter that has been introduced into the cavernous sinus outlets to the superficial middle cerebral vein. (d) Superselective venogram shows that the tip of the microcatheter has been introduced into the outlets to the superior ophthalmic vein. Note that the microcatheter has been advanced through the occluded sinus. (e) Left common carotid angiogram obtained after TVE shows complete occlusion of the dural AVF. Before placement of the coils, it is important to determine whether a microcatheter can be introduced into all outlets of the cavernous sinus.