Abstract Number ‐ 79: Flow Diversion for Traumatic Vertebral Artery Arteriovenous Fistula: A Case Report
Authors: Capone Stephen , Patel Biraj 
Published: April 2023

Introduction
Arterial pseudoaneurysms and arteriovenous fistulas of intracranial and extracranial vessels are an uncommon occurrence following blunt and penetrating trauma and are commonly treated by vessel sacrifice,dependent on collateral flow1‐3. Others have treated these cases with covered stents4 and flow diversion5. Advances in flow diversion technology have led to their use in other pathologies, including carotid cavernous fistulas6 and vertebral artery pseudoaneurysms7. We present a case of a traumatic arteriovenous fistula of the dominant vertebral artery requiring vessel preservation and reconstruction.

Methods
A 42‐year‐old male presented with a gunshot wound to the face below the right eye. Trauma imaging identified fractures of the right maxillary sinus and orbital floor. CTA of the head/neck showed a dominant right vertebral artery dissection and pseudoaneurysm with a non‐dominant left vertebral artery (VA), effectively ending in PICA.

Results
Due to the inefficient supply to the posterior circulation via the left VA, the decision was made to preserve and reconstruct the right VA and the patient was brought to the angiography suite. Angiographically, the patient was noted to have retrograde filling of the posterior circulation, basilar and right VA through the anterior circulation in injection of both ICAs, suggesting decreased antegrade flow from the injured right VA. The right VA was catheterized which showed a high‐flow, high‐grade arteriovenous fistula from the V3 segment with venous drainage into multiple extraspinal cervical and epidural cervical veins. This also identified the fistulous point at the location of the pseudoaneurysm on CTA. The diagnostic catheter was exchanged for a guide catheter, and a Phenom 27 microcatheter (Medtronic; Minneapolis, MN) was navigated into the basilar artery. A Duo microcatheter (Microvention; Aliso Viejo, CA)/Synchro 2 (Stryker; Kalamazoo, MI) standard microwire complex was used to identify the fistulous point and positioned for jailing. A Pipeline Flex 4.75×20mm (Medtronic; Minneapolis, MN) was deployed from the proximal V4 segment across the pseudoaneurysm with persistence of the AVF. A second Pipeline Flex 5×20mm was placed in telescoping fashion with persistence of the AVF. A third Pipeline Flex 5×16mm was placed in telescoping fashion and flow diversion was observed. Using the jailed catheter, the pseudoaneurysm and fistulous point were coil embolized using a combination of helical and 3D HydroSoft coils (Microvention; Aliso Viejo, CA) of varying sizes. Final angiogram demonstrated resolution of the high‐flow AVF, improvement of antegrade flow through the right vertebral artery, and a slow‐flow low‐grade fistulous communication with the posterior extraspinal cervical veins. There were no thromboembolic complications and the patient recovered well from the procedure. Follow‐up angiography at 2 months post‐treatment showed obliteration of the AVF with a small remnant pseudoaneurysm of the right V3 segment.

Conclusions
Flow diversion is viable in the setting of a traumatic arteriovenous fistula requiring reconstruction of the parent vessel.