BACKGROUND: In the endovascular treatment of symptomatic severe vertebral artery (VA) stenosis without collateral blood flow, intraprocedural acute occlusion due to thrombus rupture or lesion dissection can result in catastrophic ischemic complications in the posterior circulation. In this report, the authors describe an intentional staged angioplasty approach in which bypass surgery was performed before percutaneous transluminal angioplasty (PTA) at the stenotic lesion. This "safety bypass" was expected to provide distal collateral flow for inadvertent occlusion of the basilar artery due to dissection at the expanded segment. OBSERVATIONS: A 59-year-old man presented with severe disturbance of consciousness and stenosis of the right VA. No posterior communicating arteries or collateral flow from the contralateral VA were identified on MR angiography. The authors performed a left superficial temporal artery-superior cerebellar artery bypass in the first stage to ensure blood flow during temporary basilar artery occlusion and PTA at the stenotic lesion in the second stage of treatment. No new cerebral infarction or cerebral contusion occurred after the two procedures, and the patient was transferred to a rehabilitation facility. LESSONS: When the therapeutic risk is considered high in revascularization procedures for symptomatic intracranial vascular stenosis, intentional staged angioplasty with safety bypass is a viable option. https://thejns.org/doi/10.3171/CASE25957.
Indo et al. (Mon,) studied this question.