Transvenous Approaches to the Vertebral-Venous Plexus for Endovascular Treatment of Cervical Epidural Arteriovenous Fistulas: Anatomy and Technique.

Background: Spinal epidural arteriovenous fistulas (seAVF) are a rare subset of vascular lesions that are most commonly found in the cervical levels. Unlike spinal dural AVF, seAVF are typically supplied by multiple arteries, including direct branches from the vertebral artery, which increases the risk of nontarget embolization using a transarterial endovascular approach. In these cases, transvenous embolization may be a preferable option, but accessing the cervical epidural venous space, also termed the internal vertebral venous plexus, can be challenging and requires advanced foreknowledge of cervical venous channels. Methods: The authors review salient neurovascular anatomy and present 2 techniques for endovascular access of the cervical epidural space to treat seAVF. Results: The physiology and structure of the cervical internal vertebral venous plexus is briefly reviewed. Next, the authors describe 2 complementary methods for transvenous access to the cervical internal vertebral venous plexus via the jugular vein (cranial-caudal) and the vertebral vein (caudal-cranial). The first approach involves retrograde microcatheterization via the jugular bulb and condylar veins. The second approach involves direct antegrade approach via the vertebral vein, arising from the brachiocephalic vein. Both approaches enable stable catheter positioning for coil embolization at remote cervical levels to treat a wide spectrum of seAVF. Conclusions: Accessing the cervical epidural venous space is technically demanding and requires effective planning and knowledge of relevant spinal venous anatomy. These techniques are important tools for safe and effective endovascular treatment of seAVF.