Post-endarterectomy carotid ultrasonic duplex scanning concordance with contrast angiography.

The results of ultrasonic duplex scanning combined with spectral analysis are compared with the results of contrast angiography in patients after endarterectomy in which recurrence of carotid arterial disease was suspected. Thirty-six patients underwent a duplex scan study within 3 months of their post-operative angiogram, performed at their physician's discretion (44 studies). The overall accuracy of the method was 80%. Our ability to predict a greater than 50% diameter reduction along with total occlusion was 94%. The measure of agreement corrected for chance between arteriography and duplex scanning as expressed by the Kappa statistic was 0.675 +/- SE (K) 0.096. This level of agreement compared favorably to that of inter- and intra-observer variability in reading cerebral angiograms. The accuracy reported justifies the clinical use of ultrasonic duplex scanning in the detection of recurrent stenosis after carotid endarterectomy.