January 26, 2007 — A multidisciplinary group of neurologists and surgeons has published new guidelines to aid in screening for asymptomatic extracranial carotid artery disease, both in the general population and in selected patient groups.

The guidelines, from the American Society of Neuroimaging and cosponsored by the Society of Vascular and Interventional Neurology, appear in the January issue of the Journal of Neuroimaging.

"We have evidence that if you detect this stenosis early and treat it, using either surgery or endovascular treatment, you can actually prevent a stroke from happening," first author Adnan I. Qureshi, MD, of the University of Minnesota in Minneapolis, told Medscape.

"The issue is that there is a large body of scattered evidence that's never been accumulated in a systematic manner. The purpose of this guideline, and getting all these members together, was to go over the guidelines and synthesize it in a way that we can use it in the general population, and in selected patient populations, to detect this disease early and then intervene," Dr. Qureshi said.

Multidisciplinary Consensus

The writing committee for these guidelines includes representatives of all major groups that manage carotid stenosis, Dr. Qureshi noted.

In the article, screening recommendations are made for a variety of populations: high-risk people in the general population; patients undergoing open-heart surgery, including coronary artery bypass grafting; those with peripheral vascular disease; abdominal aortic aneurysms; and renal artery stenosis. Also discussed is when to screen patients following radiotherapy for head and neck malignancies, those following carotid endarterectomy or carotid artery stenting; patients with retinal ischemic syndromes; those with syncope, dizziness, vertigo, or tinnitus; and those with a family history of vascular diseases and hyperhomocysteinemia.

The recommendations in each section are based on the prevalence of disease and concurrent guidelines from other major professional organizations in the selected populations, such as those from the American Heart Association, although in a number of these populations, no existing guidelines were identified.

Also given a great deal of weight is the expected benefit from intervention in each of these groups. Benefit, based on that seen in the major carotid intervention trials — NASCET (North American Symptomatic Carotid Endarterectomy Trial), ACAS (Asymptomatic Carotid Atherosclerosis Study), and SAPPHIRE (Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy) — is considered against the risks of intervention in each group. "Detection is one part, but detection that can be turned around to some kind of effective prevention strategy is really the goal," Dr. Qureshi said.

What the guidelines are not designed to do is compare imaging modalities, the authors note. Most of the evidence on patient selection in the literature is based on Doppler ultrasound. "Periodic updates may be required for these recommendations as other noninvasive modalities including magnetic resonance angiography (MRA) or computed tomographic angiography (CTA) replace Doppler ultrasound," the authors write.

"The hope is that now that a well defined methodology has been put forward, physicians will use that methodology and essentially become more effective at detecting disease at an early stage," Dr. Qureshi said.

J Neuroimaging. 2007;17:19-47.