Transradial Subclavian Artery Stenting With Proximal Vertebral Artery Protection Using a Sheathless Balloon Guiding Catheter: A Case Report.

Subclavian artery (SCA) stenting is an established treatment for symptomatic stenosis; however, the optimal strategy for embolic protection of the vertebral artery (VA) remains controversial, particularly in cases with preserved antegrade VA flow. We report a case of symptomatic left SCA stenosis treated using proximal VA protection with a sheathless balloon-guiding catheter (BGC) via a transradial approach. A 77-year-old man with a history of cerebral infarction and coronary artery disease presented with dizziness. Preoperative imaging demonstrated severe stenosis of the left SCA adjacent to the VA origin with markedly reduced but preserved antegrade VA flow, indicating a potential risk of vertebrobasilar embolization during intervention. Endovascular stenting was performed through left transradial access. To achieve proximal embolic protection while minimizing access site trauma, an 8 Fr GBC was introduced using a sheathless technique and inflated at the VA origin to achieve temporary flow arrest during lesion crossing and stent deployment. After aspiration, normal antegrade flow in the VA was restored. The procedure was completed without neurological complications, and postoperative imaging confirmed improved VA flow. Proximal VA protection using a sheathless BGC via a transradial approach represents a feasible and safe strategy for SCA stenting in selected patients with preserved antegrade VA flow, particularly when distal protection devices are technically challenging.