Incidence of recurrent or residual stenosis after carotid endarterectomy.

The incidences of recurrent and residual stenosis after carotid endarterectomy have been controversial. Duplex scanning has recently provided an accurate noninvasive method of quantifying areas of arterial narrowing, and this technique was used in 122 postendarterectomy vessels from 71 men and 35 women with a mean age of 65.2 years. The average time interval between operation and scanning was 26.3 months (range 1 month to 11.76 years). Postoperative examination of the internal carotid artery revealed no stenosis in 78 vessels, less than 50 percent area reduction in 17 vessels, 50 to 75 percent stenosis in 11 vessels, more than 75 percent area reduction in 9 vessels, and total occlusion in 7 vessels. Thus, 22 percent of the vessels (27 of 122) had total occlusion or more than 50 percent area reduction after carotid endarterectomy. This is a higher rate of recurrent stenosis than was diagnosed by oculoplethysmography, where 7 of 52 vessels (13 percent) had a positive oculoplethysmogram after operation. These data show that the reported incidence of residual or recurrent stenosis after carotid endarterectomy is heavily dependent on the testing method used. Duplex scanning documents a 22 percent frequency of residual or recurrent stenosis, a figure higher than has been reported with less sensitive tests.