Accuracy of carotid compression tonography in the diagnosis of carotid artery stenosis
Norman R. Hertzer, M.D.
Department of Vascular Surgery
Thomas G. Santoscoy, M.D.
Department of General Surgery
Roger H. S. Langston, M.D.
Department of Ophthalmology
Considering the success of carotid endarterectomy in the prevention of strokes caused by symptomatic arteriosclerotic lesions of the carotid bifurcation, carotid arteriography is clearly indicated for patients who have had previous hemispheric transient ischemic attacks (TIA) or mild completed strokes. Because of the inconvenience, expense, and slight but measurable risk associated with carotid arteriography, however, noninvasive carotid testing is appropriate for patients who have asymptomatic carotid bruits or nonhemispheric neurologic symptoms (vertebrobasilar syndrome). Provided the incidence of false-negative and false-positive examinations does not exceed acceptable standards, carotid arteriography may ideally be restricted to patients with evidence of substantial carotid artery stenosis.
In 1975, Cohen et al1 reported the results of noninvasive carotid testing at The Cleveland Clinic Foundation using carotid compression tonography (CCT) in a series of 122 patients who had both CCT and carotid arteriography between April 1972 and March 1974. Of 82 patients who were found by arteriography to have greater than 50% stenosis of the internal carotid or the common carotid arteries, substantial stenosis was correctly predicted by abnormal CCT results in 76 patients (92%) with an 8% incidence of false-negative results. Ten of the 40 patients who had less than 50% stenosis of the carotid arteries also had abnormal CCT findings for a 25% incidence of false-positive results. Although CCT has continued to be the principal method for noninvasive carotid testing at this institution, several recent reports2–10 have described the accuracy of other noninvasive methods that do not require carotid compression, such as periorbital Doppler . . .