title: Appropriate frequency of carotid duplex testing following carotid endarterectomy.
abstract: BACKGROUND
  The value of carotid duplex analysis is well proven for the diagnosis of carotid bifurcation occlusive disease, but its use in the postoperative setting is less well defined.
  
  
  METHODS
  A series of 281 carotid endarterectomies were performed in 222 patients. A protocol of serial duplex examinations was established, with tests performed at the time of the first postoperative clinic visit and every 6 months thereafter. The goal of postoperative surveillance was to identify critical restenotic carotid lesions of greater than 80% diameter reduction and determine the incidence of subsequent carotid occlusion and neurologic events.
  
  
  RESULTS
  Critical restenoses developed in 25 (8.9%) of the arteries and occlusions occurred in 12 (4%). Restenosis occurred with greatest frequency during the first year after operation (5%), but continued to develop with a frequency of approximately 2% per year thereafter. Postoperative carotid occlusions occurred at a rate of approximately 1% per year. Known restenotic lesions progressed to occlusion over a mean duration of 11 months. Stroke was infrequent in patients with critical restenoses (4%) until the lesions progressed to occlusion (33%).
  
  
  CONCLUSIONS
  These observations suggest that a protocol of semiannual duplex testing into the late postoperative period may identify critical carotid restenotic lesions prior to the development of carotid occlusion and stroke.
authors.affiliation: Department of Surgery, University of Rochester, New York 14642, USA.
authors.forename: K
authors.initials: K
authors.lastname: Ouriel
authors.forename: R M
authors.initials: RM
authors.lastname: Green
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D012008:Recurrence; D013997:Time Factors; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods*