Endovascular management of iatrogenic vertebro-vertebral fistula: Black Swan event in C2 pedicle screw

Background: Vertebro-vertebral fistulas (VVF) are rare. Anatomically, they consist of an arteriovenous fistula, a direct pathological communication between vertebral veins (including the epidural vertebral venous plexus) and extradural vertebral artery. The various etiologies include trauma, iatrogenic, or spontaneous (e.g., NF-1 or Ehlers Danlos Syndrome). The clinical presentation may include acute/delayed onset of radiculopathy and/or myelopathy. They may further be characterized by the delayed onset hearing loss to tinnitus and/or the sensation of water in the ear. Case Description: We report successful endovascular management for iatrogenic VVF in a 37-year-old female who was diagnosed with an odontoid fracture (Anderson type IIC). She underwent a posterior C1 lateral masses to C2 pedicle/laminar screw fixation. An intraoperative vertebro-vertebral fistulas (VVF) was recognized during the procedure and it was managed successfully with percutaneous transarterial endovascular coiling. Conclusion: Iatrogenic VVF should immediately be suspected when the implant trajectory goes slightly off track during a C1-2 fixation. Immediate postoperative DSA and MRI are advisable, irrespective of whether the patient is symptomatic. These lesions are best managed with endovascular coiling with or without detachable balloons.