Flow disturbances following carotid endarterectomy.

Noninvasive flow dynamics in 69 carotid arteries following endarterectomy were studied. By using three parameters which measure either changes in velocity or disturbed flow, 49 per cent of the arteries demonstrated flow abnormalities consistent with a 50 per cent, or greater, reduction in diameter in at least two of the three measured parameters. Of the 31 arteries which underwent more than one postoperative study, progression of the flow abnormality was suggested by changes in the velocity ratio in 20 arteries, maximum velocity in 15 arteries and the fractional broadening term in 25 arteries.