Fueled by the stunningly positive North American Symptomatic Carotid Endarterectomy Trial (NASCET) and Asymptomatic Carotid Atherosclerosis Study (ACAS), carotid endarterectomy has dramatically increased in frequency. Similar studies from the Veterans Administration and from Europe were equally supportive of the premise that carotid endarterectomy (CEA) and aggressive management of modifiable risk factors was superior to risk factor management alone. However, these studies are more than a decade old and do not reflect contemporary results of carotid surgery. Nor do they represent optimal contemporary medical treatment protocols—beta blockers, statins, and potent antiplatelet agents have strengthened the medical armamentarium. Even so, NASCET was overwhelmingly in support of surgery for symptomatic patients, particularly those with higher grades of carotid stenosis (≥70%). Patients with lesser degrees of stenosis (50% to 69%) also benefited, but the benefit was less pronounced. ACAS also significantly favored carotid endarterectomy in properly selected asymptomatic patients with ≥60% stenosis. Both studies restricted patient entry to individuals less than or equal to 80 years of age and of reasonable surgical risk. Appropriate to the time, these studies do not reflect contemporary surgical outcomes, nor do they provide guidance for the large and increasing population of octogenarians and even some nonagenarians who are in general good health with critical lesions in their carotid arteries. Patient-specific recommendations must be made using contemporary outcomes and techniques while balancing risk and benefit. These are uncharted waters. My current practice is to offer carotid endarterectomy to “fit” patients of any age with symptomatic carotid lesions. Symptoms that are not classical for hemispheric transient ischemic attacks (TIAs) are not sufficient (i.e., dizziness, vertigo, or posterior circulation symptoms). Likewise, some patients have hemispheric TIAs from other than the carotid bifurcation—i.e., an embolus from a cardiac source, the aortic arch or the great vessels, paradoxical embolism, or an intracranial source. CEA in asymptomatic patients with ≥70% stenosis who are reasonable risks are also warranted. This 70% threshold is slightly more stringent than the ACAS recommendations but has worked well in practice. Also, the definition of “high risk” used by advocates of alternative procedures does not properly identify a high-risk CEA population.

For many years arch aortography and fourvessel pancerebral angiography was the gold standard for planning and defining the relevant anatomy prior to carotid endarterectomy. However, this diagnostic study is associated with a stroke risk that at times equals or exceeds the risk of stroke from carotid surgery. At many centers carotid duplex studies are very reliable and are used as the sole pre-operative study. Well-done duplex scans from accredited vascular laboratories are sufficient in the vast majority of cases. Studies from laboratories or offices not accredited by the Inter-society Committee for the Accreditation of Vascular Laboratories (ICAVL) are suspect, due to over- and under-reading carotid
duplex scans. Newer imaging techniques, including Magnetic Resonance Angiography (MRA) and fast (32-slice) and ultra-fast (64-slice) CT scans (CT angiography) are increasingly used but are not yet competitive with either conventional angiography or duplex scanning. I prefer to use carotid duplex scanning in the vast majority of cases and reserve conventional angiography for redo procedures, complex procedures, atypical clinical presentations, patients who have the suspicion of arch or intracranial disease, or when the duplex scan is difficult to interpret or produces an indeterminate result. I am much less enthusiastic about MRA, finding that it consistently over-reads the severity of stenosis when compared to duplex scan, conventional angiography, or the findings at surgery. The ultra-fast CT scanners and CT angiography are sufficiently new that there is not yet much experience with their use for carotid disease. They also entail significant radiation exposure. Both CT and MRA are certain to soon be more readily available, and more reliable imaging protocols for carotid disease will be developed. Whether they can be cost competitive with other modalities remains to be seen.