A new draining or emissary vein originating from terminal segment of sigmoid venous sinus?

The venous efflux from cerebral dural venous sinus into the extracranial venous drainage is predominantly based on sigmoid venous sinus draining into the internal jugular vein. In the fetal stage, the rapid growth of cerebral hemispheres leads to an enlargement of transverse venous sinuses in somewhat disproportionate manner to growth of sigmoid venous sinus and internal jugular vein. Therefore, emissary veins are necessary to ensure adequate efflux pathways for intracranial venous drainage. A variable number of emissary veins may persist after the fetal stage [2–4]. Some of the important emissary veins include the mastoid emissary vein [2,3] that connect the transverse sinus with the posterior auricular or occipital veins, and the anterior and posterior condyA.A lateral projection of cerebral angiogram demonstrating the new vein in the venous phase (dashed arrows). Notice the narrow internal jugular vein anterior to the new vein.