Revison of DEGUM Ultrasound Criteria for Grading Internal Carotid Artery Stenoses and Transfer to NASCET Measurement

Since 1986, German ultrasound criteria for grading carotid stenosis have followed the local diameter reduction percentage consistent with the definition used in the European Carotid Surgery Trial (ECST) definition. To overcome the confusion caused by the coexisting grading method used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET), a German interdisciplinary council on carotid artery stenosis has recommended the implementation of the NASCET grading system (distal diameter reduction percentage) as the standard. The multi-parametric German DEGUM ultrasound criteria consisting of combined Doppler and imaging criteria have consequently been revised and transferred to the NASCET definition. In addition, a novel differentiation between main (primary) and additional (secondary) criteria has been proposed. When these ultrasound criteria are combined, vascular sonography allows reliable grading of carotid disease.