Rare Etiology of Bow Hunter's Syndrome and Systematic Review of Literature

Background—Bow Hunter's Syndrome is a mechanical occlusion of the vertebral artery which leads to a reduction in blood flow in posterior cerebral circulation resulting in transient reversible symptomatic vertebrobasilar insufficiency. Case Description—We present a case of Bow Hunter's syndrome in a 53-year-old male that occurred after the patient underwent surgical correction of a proximal left subclavian artery aneurysm. Shortly after the surgery, the patient began to complain of transient visual changes, presyncopal spells, and dizziness upon turning his head to the left. A transcranial doppler ultrasound confirmed the diagnosis of Bow Hunter's syndrome. Systemic Review—We analyzed the data on 153 patients with Bow Hunter's syndrome from the literature. An osteophyte was the most common cause of vertebral artery occlusion, and left vertebral artery was more commonly involved in patients with Bow Hunter's syndrome. Dynamic angiography was the definitive imaging modality to confirm the diagnosis, and surgery was most successful in alleviating symptoms. Conclusion—We believe that this is the first case of iatrogenic Bow Hunter's syndrome after surgical intervention for an aneurysm repair, and the largest review of literature of Bow Hunter's syndrome. Dynamic angiography is the gold standard for the diagnosis of Bow Hunter's syndrome. Surgery should be considered as the primary treatment approach in these patients, especially those who have bony compression as the etiology.