Vertebral arteriovenous fistula that developed in the same place as a previous ruptured aneurysm: a case report

BACKGROUND Aneurysms of the extracranial vertebral artery (VA) and vertebral arteriovenous fistulas (VAVFs) are relatively rare diseases. The most frequent cause of both diseases is trauma. Atraumatic lesions are less common. Presented here is a case of atraumatic AVF of the extracranial VA that developed in the same location as a previous ruptured aneurysm of the ipsilateral VA that was originally treated by proximal occlusion 11 years earlier. METHODS A 40-year-old woman presented with a massive hematoma in the upper posterior neck region caused by the rupture of an extracranial VA aneurysm. Proximal occlusion of the VA was performed by use of a detachable balloon. She enjoyed good health for 11 years, then she noticed a pulsatile bruit. Angiograms revealed an AVF between the left VA that was fed by collateral circulation and the paravertebral venous plexus. Incidentally found were soft tissue masses in the left retroauricular and the right suboccipital regions. Also, skull X-ray films showed multiple bony defects. Biopsy of the subcutaneous mass was performed in the hope of obtaining clues as to which pathological processes had weakened the artery. RESULTS As direct transarterial access to the fistula was out of the question, the fistulous compartment of the paravertebral venous plexus was tightly packed with multiple platinum coils effected by the transfemoral approach. A histological examination of the specimen revealed features of a neurofibroma, and a diagnosis of neurofibromatosis Type 1 was established. CONCLUSIONS In this case, transvenous embolization of the VAVF was successfully performed. The fragility of the arterial wall, related to neurofibromatosis Type 1, was considered to contribute to the development of the aneurysm and AVF.