External carotid stenting for symptomatic stenosis in a patient with patent EDAS for Moyamoya disease

Background: Moyamoya disease is characterized by progressive narrowing of the internal carotid artery (ICA). Symptomatic patients typically undergo cerebrovascular intervention via extracranial-intracranial (EC-IC) bypass, most often with the use of the superficial temporal artery. This case of Moyamoya disease is of particular interest as the patient presented with a unilateral atherosclerotic external carotid artery (ECA) stenosis after EC-IC bypass that eliminated the benefit of his original surgery, resulting in a symptomatic presentation. Clinical presentation: A 53-year-old man presenting with Moyamoya disease and known left ICA occlusion had received a bilateral encephaloduroarteriosynangiosis (EDAS) bypass 10 years previously. He re-presented complaining of right-sided tingling, weakness, and numbness radiating up the arm. CT angiography indicated significant stenosis of the left ECA. ECA angioplasty and stenting with a distal protection device resulted in resolution of his symptoms. Conclusions: This case illustrates that a patient presenting with Moyamoya disease and concurrent symptomatic ECA stenosis post-EDAS can be effectively and safely treated with ECA stenting.