Is duplex follow-up cost-effective in the first year after carotid endarterectomy?
Recent reports have suggested that duplex scanning is an ideal method to noninvasively assess the incidence of recurrent carotid stenosis. However, the timing and frequency of the follow-up studies are controversial. In the present study, 150 patients underwent 173 carotid endarterectomy procedures over a 2 year period. In the postoperative period, a total of 210 duplex studies were carried out on 117 carotid arteries. 21.4 percent of the 117 arteries studied had recurrent stenosis of 16 percent or greater at a mean postoperative follow-up of 15.2 +/- 3 months. Recurrent stenoses were detected early after operation; 96 percent were detected at or before 15 months postoperatively. Patients with recurrent stenoses remained stable and had infrequent symptoms. Several risk factors placed the patient at increased risk for recurrent carotid stenosis: presence of contralateral disease (defined as stenosis of 50 percent or greater), use of tacking sutures, and continued smoking in the postoperative period. Although it remains important for researchers to thoroughly investigate the natural history of atherosclerosis of the extracranial carotid artery, including those changes that occur after carotid endarterectomy, our results indicate that frequent duplex scanning in the first postoperative year is unnecessary and is not cost-effective. Duplex follow-up studies 1 and 12 months after carotid endarterectomy are sufficient for assessing the problem of recurrent stenosis in the first postoperative year.