Carotid endarterectomy in an asymptomatic patient with contralateral agenesis of the internal carotid artery.

A 64-year-old man was referred to the vascular surgery department with an incidental finding of right internal carotid artery stenosis during thyroid ultrasound imaging. Carotid artery color duplex revealed an ulcerated type III plaque producing stenosis of the right internal carotid artery of 70% and agenesis of the left internal carotid artery. Further imaging with computed tomography angiography confirmed the initial findings and excluded cerebral vascular malformations and ischemic cerebral infarcts.