Occipital artery-to-posterior inferior cerebellar artery bypass for treatment of bilateral vertebral artery occlusion: the role of quantitative magnetic resonance angiography noninvasive optimal vessel analysis: technical case report.

OBJECTIVE: Patients with partial or complete bilateral vertebral artery occlusion often present with signs and symptoms of transient ischemic attacks or infarction. Advances in phase contrast magnetic resonance imaging have led to noninvasive assessment of volumetric blood flow rates and direction that help in the workup and management of these patients.

CLINICAL PRESENTATION: We present the case of a patient with symptoms of vertebrobasilar insufficiency without previous transient ischemic attacks or stroke. Quantitative magnetic resonance angiography (QMRA) demonstrated bilateral vertebral artery occlusion with reversal of flow in the basilar and vertebral arteries to the level of the posterior inferior cerebellar arteries bilaterally. A prominent right posterior communicating artery filled the basilar artery and proximal vertebral arteries.

INTERVENTION: The presence of reversal and diminished flow in the basilar and vertebral arteries suggested that occipital artery-to-posterior inferior cerebellar artery bypass would improve posterior circulation, relieve symptoms, and reduce the risk of infarction. Postoperative QMRA and angiography confirmed revascularization, and QMRA confirmed correction of blood flow direction.

CONCLUSION: This case illustrates the potential of QMRA as part of a comprehensive cerebrovascular assessment, operative planning, and follow-up of patients with vertebrobasilar insufficiency.