CAROTID DUPLEX SCAN VERSUS ANGIOGRAPHY IN EVALUATION OF CAROTID-ARTERY DISEASE

Angiography is presently felt to be the most accurate means of evaluat ing the carotid artery bifurcation, and is required preoperatively by most vascular surgeons. Arterial digital subtraction angiography (DSA) is the method commonly used. Angiography, however, is expensive and i nvasive, with significant morbidity and mortality. Duplex scanning (DS ) has gained acceptance as a screening technique and has recently been advocated as the sole preoperative study in several centers because i t is non-invasive and has an accuracy that is equal to or better than angiography. This study preoperatively evaluated 41 carotid arteries i n 38 patients by arterial digital subtraction angiography and duplex s canning, and the results were compared to the surgical specimen. One a rtery was excluded because of an inadequate duplex scan, leaving 40 ar teries studied by both techniques. Forty arteries (100%) studied by du plex scans corresponded with the surgical specimen, whereas only 31 ar teries (77.5%) studied by DSA corresponded with the surgical specimen. Nine arteries (22.5%) studied by DSA had stenosis at the time of surg ery significantly greater than predicted by DSA. Three arteries (7%) w ere felt to be normal by DSA, but had approximately 80 per cent stenos is by DS and at surgery. Our findings. indicate that duplex scanning a t our institution is more accurate than arterial DSA in determining pe rcent diameter stenosis and plaque morphology of carotid arteries.