Carotid artery stenting in a patient with right-sided aortic arch with an aberrant left subclavian artery.

A right-sided aortic arch with an aberrant left subclavian artery is a rare anatomical variation. We report a case treated with carotid artery stenting (CAS) for a patient with a right-sided aortic arch with an aberrant left subclavian artery. A 72-year-old man presented right hemiparesis due to acute brain infarction. Neck CT angiography showed 70% stenosis in the left internal carotid artery (ICA). We diagnosed acute brain infarction as artery-to-artery embolism due to ICA stenosis and decided to perform carotid artery stenting (CAS) for symptomatic ICA stenosis. CT angiography to evaluate an access route to the lesion incidentally showed the right-sided aortic arch with an aberrant left subclavian artery. An intraoperative aortogram showed a right-sided aortic arch. The guiding catheter was carefully introduced up to the left common carotid artery. CAS was performed with a proximal balloon and distal filter protection. The stenotic area was restored, and the patient was discharged without suffering recurrent attacks. Although a right-sided aortic arch with an aberrant left subclavian artery is a very rare anatomical variation, it can be encountered in neuroendovascular treatment, and therefore knowledge of this anatomical variation is important.