title: The value and economic analysis of routine postoperative carotid duplex ultrasound surveillance after carotid endarterectomy.
abstract: BACKGROUND
  Several studies have reported on the role of postoperative duplex ultrasound surveillance after carotid endarterectomy (CEA) with varying results. Most of these studies had a small sample size or did not analyze cost-effectiveness.
  
  
  METHODS
  We analyzed 489 of 501 CEA patients with patch closure. All patients had immediate postoperative duplex ultrasound examination and were routinely followed up both clinically and with duplex ultrasound at regular intervals of 1 month, 6 months, 12 months, and every 12 months thereafter. A Kaplan-Meier analysis was used to estimate the rate of ≥50% and ≥80% post-CEA restenosis over time and the time frame of progression from normal to ≥50% or ≥80% restenosis. The cost of post-CEA duplex surveillance was also estimated.
  
  
  RESULTS
  Overall, 489 patients with a mean age of 68.5 years were analyzed. Ten of these had residual postoperative ≥50% stenosis, and 37 did not undergo a second duplex ultrasound examination and therefore were not included in the final analysis. The mean follow-up was 20.4 months (range, 1-63 months), with a mean number of duplex ultrasound examinations of 3.6 (range, 1-7). Eleven of 397 patients (2.8%) with a normal finding on immediate postoperative duplex ultrasound vs 4 of 45 (8.9%) with mild stenosis on immediate postoperative duplex ultrasound progressed to ≥50% restenosis (P = .055). Overall, 15 patients (3.1%) had ≥50% restenosis, 9 with 50% to <80% and 4 with 80% to 99% (2 of these had carotid artery stenting reintervention), and 2 had late carotid occlusion. All of these were asymptomatic, except for one who had a transient ischemic attack. The mean time to ≥50% to <80% restenosis was 14.7 months vs 19.8 months for ≥80% restenosis after the CEA. Freedom from restenosis rates were 98%, 96%, 94%, 94%, and 94% for ≥50% restenosis and 99%, 98%, 97%, 97%, and 97% for ≥80% restenosis at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. Freedom from myocardial infarction, stroke, and deaths was not significantly different between patients with and without restenosis (100%, 93%, 83%, and 83% vs 94%, 91%, 86%, and 79% at 1 year, 2 years, 3 years, and 4 years, respectively; P = .951). The estimated charge of this surveillance was 3.6 × 489 (number of CEAs) × $800 (charge for carotid duplex ultrasound), which equals $1,408,320, to detect only four patients with ≥80% to 99% restenosis who may have been potential candidates for reintervention.
  
  
  CONCLUSIONS
  This study shows that the value of routine postoperative duplex ultrasound surveillance after CEA with patch closure may be limited, particularly if the finding on immediate postoperative duplex ultrasound is normal or shows minimal disease.
authors.affiliation: Department of Surgery, West Virginia University, Charleston, WVa. Electronic address: ali.aburahma@camc.org.
authors.forename: Ali F
authors.initials: AF
authors.lastname: AbuRahma
authors.affiliation: Department of Surgery, West Virginia University, Charleston, WVa.
authors.forename: Mohit
authors.initials: M
authors.lastname: Srivastava
authors.affiliation: Department of Surgery, West Virginia University, Charleston, WVa.
authors.forename: Zachary
authors.initials: Z
authors.lastname: AbuRahma
authors.affiliation: Department of Surgery, University of Alabama, Birmingham, Ala.
authors.forename: Will
authors.initials: W
authors.lastname: Jackson
authors.affiliation: Department of Surgery, West Virginia University, Charleston, WVa.
authors.forename: Albeir
authors.initials: A
authors.lastname: Mousa
authors.affiliation: Department of Surgery, West Virginia University, Charleston, WVa.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Stone
authors.affiliation: CAMC Health Education and Research Institute, Charleston, WVa.
authors.forename: L Scott
authors.initials: LS
authors.lastname: Dean
authors.affiliation: West Virginia School of Osteopathic Medicine, Lewisburg, WVa.
authors.forename: Jason
authors.initials: J
authors.lastname: Green
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000191:economics / Q000601:surgery; D018450:Disease Progression; D016894:Endarterectomy, Carotid / Q000191:economics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000191:economics; D012008:Recurrence; D012189:Retrospective Studies; D018616:Ultrasonography, Doppler, Duplex / Q000191:economics*