Reporting Standards for Carotid Artery Angioplasty and Stent Placement

Measurement of carotid stenosis using North American Symptomatic Carotid Endarterectomy Trial (NASCET), European Carotid Surgery Trial (ECST), and Common Carotid (CC) methods. All three methods demonstrate a high degree of reproducibility overall. The NASCET method used most frequently in the United States is reliable but tends to underestimate the degree of stenosis. The NASCET ratio should not be applied if there is near-occlusion with reduction in the diameter of the cervical internal carotid artery beyond the stenosis. Such a reduction in the diameter of the internal carotid artery beyond the site of stenosis would consequently underestimate the severity of stenosis. CC and ECST methods grade the stenosis similarly and generally are in agreement. For atherosclerotic disease that narrows the carotid bulb, the percentage difference between NASCET and ECST increases. Carotid stenosis measured at ultrasound tends to correlate better with ECST and CC methods ().