Abstract 286: Endovascular Management of Pediatric Vertebro‐Vertebral Arterio‐Venous Fistula: Case report
Authors: Pillai Bharat , Doheim Mohamed F. , Nidamanuri Priya , Mahat Bishow C. , Yilmaz Sabri , Greene Stephanie , Al‐Bayati Alhamza R. 
Published: March 2024

Introduction
Vertebro‐vertebral arteriovenous fistula (VV‐AVF) is a rare vascular malformation with abnormal high flow shunt between extracranial vertebral artery and an adjacent vertebral vein plexus without intervening capillaries.1 While seen in both adult and pediatric populations, the majority of the VV‐AVFs seen in childhood are largely congenital, seen in the setting of connective tissue diseases such as Ehler‐Danlos Syndrome, Neurofibromatosis type 1, and Marfan’s syndrome, with abnormal involution of the proatlantal system also thought to be implicated.2,3,4 Approximately 70% of the presenting population are symptomatic at presentation, with a pulsatile mass over the side of the neck or pulsatile tinnitus. Additionally, symptoms of vertebrobasilar insufficiency including gait abnormalities, limb weakness, vertigo, recurrent vomiting, diplopia, and in severe cases, cardiac decompensation can also be seen.5

Methods
This is a case report of a 2‐year‐old boy presented to our pediatric neurovascular center of excellence with a progressively enlarging pulsatile left neck mass appreciated a year ago. Further evaluation with neck MRA followed by catheter cerebral angiogram revealed an upper cervical AVF with primary arterial feeders from V3 segment of the left vertebral artery, enlarged left occipital artery, and retrograde filling via the right vertebral artery into the left V4 with a direct shunt into a large venous pouch which drained into the vertebral venous plexus.

Results
Given the progressive enlargement of the mass, location of AVF, and concern for detrimental subsequent venous congestion, decision was made to pursue elective endovascular embolization of the VV‐AVF. The goal was set to obtain complete occlusion of the venous pouch to obliterate all arterial inflow contribution and prevent further recruitment. Occipital artery catheterization was attempted however given the redundant anatomical loops; optimum microcatheter navigation was not feasible. Given the non‐dominant configuration of the left VA, along with the presence of left AICA‐PICA system off the basilar trunk, coil embolization of the venous pouch followed by sacrifice of the V3 segment left VA was achieved satisfactorily leading to obliteration of the AVF along with all the arterial contributions from bilateral vertebral arteries and left occipital artery (Figure‐1). Given the potential vertebrobasilar inadvertent embolization, the procedure was performed under continuous neurophysiological monitoring and post‐periprocedural therapeutic anticoagulation. The patient tolerated the procedure well without any intraoperative issues. He was monitored in the pediatric ICU for 24 hours after the procedure, and subsequently discharged home.

Conclusion
We report a successful endovascular coil embolization of a VV‐AVF. To our knowledge, this is the youngest reported case where endovascular technique was successfully utilized to achieve cure of such high flow VV‐AVF in this 2‐year‐old patient. Systematic and methodical angiographic analyses with close post‐procedural monitoring are pivotal in ensuring successful outcomes.