Clinical outcome of patients with acute posterior circulation stroke and bilateral vertebral artery occlusion.

Background and Introduction: Patients presenting with posterior circulation acute ischemic events are occasionally noted to have occlusion of bilateral vertebral arteries with basilar artery blood flow entirely dependent from the anterior circulation. There is limited data about prognosis of such patients in literature.
Methods: Patients with acute posterior circulation ischemic stroke and bilateral vertebral artery occlusion (including contra-lateral hypoplastic vertebral artery without contribution to the basilar artery system) were identified prospectively from two academic centers. Data including clinical presentation, medical management, angiographic findings, recurrent events and outcome were collected and reported.
Results: A total of 4 patients presenting with acute ischemic events in the posterior circulation were identified to have bilateral vertebral artery occlusion at our center. One additional patient had a vertebral artery occlusion and a contra-lateral hypoplastic vertebral artery. In the functional evaluation of the blood flow with catheter angiography, the basilar artery was filling from the anterior circulation, with no antegrade flow from bilateral vertebral arteries injection in all 5 patients. Patients were treated with anti-platelets (n=4) or started on anti-coagulation after failing anti-platelet therapy (n=2). All patients had recurrent ischemic stroke with new ischemic lesions proven by diffusion weighted images on MRI within 2 to 70 days after the initial event.
Conclusion: Patients with acute posterior circulation ischemic stroke and bilateral vertebral artery occlusion are at high risk of having early recurrent ischemic events. Reestablishment of the antegrade vertebro-basilar blood flow through endovascular re-canalization might be an option to decrease stroke recurrence in selected patients with acute posterior circulation stroke and bilateral vertebral artery occlusion.