Endovascular Recanalization of Non-Acute Vertebrobasilar Occlusion in Progressive Posterior Circulation Ischemia: A Case Report

Background: Unlike acute basilar artery occlusion, non-acute vertebrobasilar occlusion has limited evidence for intervention and requires individualized risk assessment. Case Presentation: A 62-year-old woman developed progressive vertigo, diplopia, dysarthria, and gait ataxia over ten days. Dual antiplatelet therapy was started after posterior circulation ischemia was suspected, but symptoms continued to progress. MRI showed acute to subacute left cerebellar infarction, and CTA showed absent antegrade basilar opacification with collateral distal filling. DSA showed distal left vertebral artery occlusion, retrograde basilar filling through posterior communicating artery collaterals, and hypoplastic right vertebral artery. Endovascular recanalization was performed after multidisciplinary review and informed consent. Intraluminal crossing, stepwise angioplasty, and stent reconstruction restored antegrade basilar flow without angiographic complications. NIHSS improved from 5 to 2 at discharge, and mRS was 1 at 30 days. No follow-up vascular imaging was available. Conclusions: This case illustrates technical feasibility in selected non-acute vertebrobasilar occlusion, but does not establish medical treatment failure, causal recovery, generalizable safety, or long-term durability.