A Transverse–Sigmoid Sinus Dural AV Fistula: A Tiny but Critical Bridge

This video presents a case of a 54-year-old man with a transverse-sigmoid sinus dural arteriovenous fistula, characterized by complex arterial feeders and retrograde venous reflux causing symptoms of intracranial hypertension.

The neurointerventional approach involved transvenous coiling and Onyx embolization, complicated by a residual shunt with reflux into a critical bridging vein draining to the brainstem.

The case highlights the importance of detailed angiographic assessment, selective injections for detecting hidden reflux pathways, and careful management of hemodynamic changes during intervention to avoid complications such as cranial nerve palsy or worsening reflux.