title: Standard duplex criteria overestimate the degree of stenosis after eversion carotid endarterectomy.
abstract: OBJECTIVE
  The eversion technique for carotid endarterectomy (eCEA) offers an alternative to longitudinal arteriotomy and patch closure (pCEA) for open carotid revascularization. In some reports, eCEA has been associated with a higher rate of >50% restenosis of the internal carotid when it is defined as peak systolic velocity (PSV) >125 cm/s by duplex imaging. Because the conformation of the carotid bifurcation may differ after eCEA compared with native carotid arteries, it was hypothesized that standard duplex criteria might not accurately reflect the presence of restenosis after eCEA.
  
  
  METHODS
  In a case-control study, the outcomes of all patients undergoing carotid endarterectomy by one surgeon during the last 10 years were analyzed retrospectively, with a primary end point of PSV >125 cm/s. Duplex flow velocities were compared with luminal diameter measurements for any carotid computed tomography arteriography or magnetic resonance angiography study obtained within 2 months of duplex imaging, with the degree of stenosis calculated by the methodology used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) as well as cross-sectional area (CSA) reduction. Simulations were generated and analyzed by computational model simulations of the eCEA and pCEA arteries.
  
  
  RESULTS
  Eversion and longitudinal arteriotomy with patch techniques were used in 118 and 177 carotid arteries, respectively. Duplex follow-up was available in 90 eCEA arteries at a median of 16 (range, 2-136) months and in 150 pCEA arteries at a median of 41 (range, 3-115) months postoperatively. PSV >125 cm/s was present at some time during follow-up in 31% of eCEA and pCEA carotid arteries, each, and in the most recent duplex examination in 7% after eCEA and 21% after pCEA (P = .003), with no eCEA and two pCEA arteries occluding completely during follow-up (P = .29). In 19 carotid arteries with PSV >125 cm/s after angle correction (median, 160 cm/s; interquartile range, 146-432 cm/s) after eCEA that were subsequently examined by axial imaging, the mean percentage stenosis was 8% ± 11% by NASCET, 11% ± 5% by ECST, and 20% ± 9% by CSA criteria. For eight pCEA arteries with PSV >125 cm/s (median velocity, 148 cm/s; interquartile range, 139-242 cm/s), the corresponding NASCET, ECST, and CSA stenoses were 8% ± 35%, 26% ± 32%, and 25% ± 33%, respectively. NASCET internal carotid diameter reduction of at least 50% was noted by axial imaging after two of the eight pCEAs, and the PSV exceeded 200 cm/s in each case.
  
  
  CONCLUSIONS
  The presence of hemodynamically significant carotid artery restenosis may be overestimated by standard duplex criteria after eCEA and perhaps after pCEA. Insufficient information currently exists to determine what PSV does correspond to hemodynamically significant restenosis.
authors.affiliation: Department of Surgery, Medical University of South Carolina, Charleston, SC.
authors.forename: Travis
authors.initials: T
authors.lastname: Benzing
authors.affiliation: Department of Surgery, Medical University of South Carolina, Charleston, SC.
authors.forename: Cameron
authors.initials: C
authors.lastname: Wilhoit
authors.affiliation: Department of Surgery, Medical University of South Carolina, Charleston, SC.
authors.forename: Sharee
authors.initials: S
authors.lastname: Wright
authors.affiliation: Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC.
authors.forename: P Aaron
authors.initials: PA
authors.lastname: McCann
authors.affiliation: Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC.
authors.forename: Susan
authors.initials: S
authors.lastname: Lessner
authors.affiliation: Ralph H. Johnson Department of Veterans Affairs Medical Center, Charleston, SC; Department of Surgery, Medical University of South Carolina, Charleston, SC. Electronic address: brothete@musc.edu.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Brothers
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D003198:Computer Simulation; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013022:South Carolina; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color