Parallel transverse-sigmoid sinus harboring dural arteriovenous malformation. How to differentiate the pathological and normal sinus in order to treat and preserve patency and function.

An unusual case of dural arteriovenous malformation (DAVM) harboring a parallel transverse-sigmoid sinus (TSS) is presented. The patient had a 2-year history of left-sided pulsatile tinnitus in the left ear refractory to medical management. Angiography demonstrated a DAVM involving the left TSS. Super-selective transvenous dural sinus occlusion of the DAVM situated at the pathological compartment of the TSS provided cure. We were able to spare the normal compartment providing anatomical venous drainage from this system.