Intraoperative duplex scanning reduces the incidence of residual stenosis after carotid endarterectomy.

We studied the effect of intraoperative duplex scanning on the incidence of residual and recurrent stenosis and stroke after carotid endarterectomy (CEA). We retrospectively analyzed 98 veteran patients undergoing 106 consecutive CEAs between July 1990 and June 1994. Follow-up duplex scans were available for 86 cases (81%, mean follow-up 20 months). There were no perioperative deaths. Intraoperative duplex scans were obtained in 39 (45%) of 86 CEAs. The incidence of residual stenosis was lower in the patients scanned at the time of surgery (O of 39) than in those who underwent CEA without intraoperative scan (7 of 47, P < 0.04). One patient who did not receive intraoperative duplex scanning underwent redo CEA for symptomatic residual stenosis due to an intimal flap of the carotid artery. Operative management was changed in 9 of 39 cases because of abnormal intraoperative duplex scans, with no postoperative strokes or residual/recurrent stenosis. The incidence of recurrent stenosis was not different in the two groups (2 of 39 vs 2 of 47, ns). There was no difference in stroke rate. There were three strokes, one perioperative and two postoperative (mean 3.5 months, range 0.5 to 9). Two of the three patients did not undergo an intraoperative duplex scan, but none had developed restenosis >50% over a mean of 21 months of follow-up. Intraoperative duplex scanning significantly reduced the incidence of residual stenosis, but did not affect the incidence of recurrent stenosis or stroke following CEA.