Noninvasive techniques for diagnosis of carotid artery disease.

Abstract

A variety of noninvasive techniques have been advocated for the detection of carotid artery disease. These techniques may be divided into 2 major groups: those that assess the carotid bifurcation directly and those that assess the hemodynamics of the carotid system distal to the bifurcation. An increasing number of reports suggest that these techniques can be utilized in varying combinations to obtain information about the extent of atherosclerosis at the carotid bifurcation, particularly for lesions that produce 60-75% or greater stenosis, in which hemodynamic changes might be expected. There are certain situations in which this information may be of clinical merit, but one must be cautious about allowing this information to indicate 1 type of therapy over another. The problem is not only whether these studies can be used to detect carotid atherosclerosis that can be treated, but also whether these studies can be utilized to predict which patients should have their carotid atherosclerosis treated. If not, physicians will continue to find themselves in the position of detecting many patients with atherosclerosis and not knowing what to do with them. At present, the applicability of the studies to clinical practice will vary, and depends on the clinician''s predetermined bias as to the efficacy of the various available treatment modalities. This is illustrated by reviewing 3 common clinical situations evaluation of symptomatic patients, routine screening of asymptomatic patients and screening of asymptomatic patients before surgery.