Does carotid duplex imaging render angiography redundant before carotid endarterectomy?

Carotid duplex imaging is now recognized as the best non-invasive screening test for carotid artery stenosis. The evidence for its use as the sole diagnostic imaging modality prior to carotid endarterectomy is examined. Providing it is carried out by experienced trained operators using validated duplex criteria, carotid duplex imaging is safe, highly sensitive and specific, and superior to angiography at plaque characterization and evaluation of flow disturbance. Cerebral CT or MRI should be performed if symptoms are atypical or if there is an evolved stroke. Angiography is required when duplex imaging is suboptimal or equivocal, in the presence of atypical symptoms or uncommon vascular abnormalities. In the majority of patients requiring endarterectomy for symptomatic high grade ICA stenosis, angiography seldom adds relevant information, and clinical assessment and carotid duplex imaging alone can be safely used in preoperative assessment.