Spontaneous obliteration of spontaneous vertebral arteriovenous fistula associated with fibromuscular dysplasia after partial surgery: A case report.

We describe a patient with spontaneous obliteration of spontaneous vertebral arteriovenous fistula (VAVF) associated with fibromuscular dysplasia (FMD) after partial surgery. A 52-year-old hypertensive female woke up one morning with left shoulder pain and weakness of the left upper extremity. A few days later, she developed left-sided audible bruit. She was treated for left frozen shoulder and supportive treatment for audible bruit for four years. She was referred from her general physician to a neurosurgeon because of left arm weakness. Physical examination showed signs of cervical radiculomyelopathy. Magnetic resonance imaging (MRI) showed an extradural mass on the left side of the cervical spinal canal from level C2 to C6. Provisional diagnosis was epidural vascular tumour. Laminectomy and partial removal of the mass was performed at level C5 to C6. Pathological report revealed suspected vascular malformation. Postoperative MRI showed thrombosed epidural vascular structure. Angiography showed dysplastic changes of both vertebral arteries representing FMD with VAVF of the left vertebral artery at level C1-C2. Two years after surgery, follow-up MRI demonstrated complete spontaneous resolution of the large thrombosed epidural vein. Disappearance of her audible bruit immediately after surgery and gradual improvement of her cervical radiculomyelopathy were observed after two years of clinical follow-up. From the literature, we found another 11 patients with 12 VAVFs who had spontaneous obliteration or cure of their fistulas. In the present case, spontaneous obliteration of the fistula seems to correlate with surgery inducing closure of the epidural venous exit leading to thrombosis of the enlarged epidural draining vein.