title: Renal artery duplex ultrasound criteria for the detection of significant in-stent restenosis.
abstract: OBJECTIVE
  To define velocity criteria by ultrasonography for the detection of hemodynamically significant (>60%) renal artery in-stent restenosis (ISR).
  
  
  BACKGROUND
  The restenosis rate after renal artery stenting ranges between 10% and 20%. While duplex ultrasound criteria have been validated for native renal artery stenosis, there are no uniformly accepted validated criteria for stented renal arteries.
  
  
  METHODS
  Vascular laboratory databases from two academic medical centers were retrospectively reviewed for patients who underwent renal artery stenting followed by duplex ultrasound evaluation and angiography (CT angiography or catheter angiography) as the gold standard.
  
  
  RESULTS
  A cohort of 132 stented renal arteries that had angiographic comparisons was analyzed. Eighty-eight renal arteries demonstrated 0-59% stenosis while 44 renal arteries revealed 60-99% stenosis by angiography. Both the mean peak systolic velocity (PSV) and the renal artery-to-aortic ratio (RAR) were significantly higher in renal arteries with 60-99% restenosis compared with those with 0-59% restenosis (PSV: 382 cm/sec ± 128 vs. 129 cm/sec ± 62, P<0.001; RAR: 5.3 ± 2.4 vs. 2.1 ± 1.0, P <0.001). The optimal PSV and RAR cutoffs for detecting 60-99% ISR were calculated by receiver operator characteristics curve analysis. The velocity criteria that are associated with these results will be discussed.
  
  
  CONCLUSIONS
  Duplex ultrasonography is an accurate technique to identify significant restenosis in stented renal arteries. The PSV and RAR cutoffs for detecting renal artery ISR are higher than those in native, unstented renal arteries. A normal duplex ultrasound after renal artery stenting virtually excludes significant restenosis.
authors.affiliation: Zena and Michael A. Wiener Cardiovascular Institute and Marie-Josée and Henry R. Kravis Center for Cardiovascular Health, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Ian
authors.initials: I
authors.lastname: Del Conde
authors.forename: Ira D
authors.initials: ID
authors.lastname: Galin
authors.forename: Biana
authors.initials: B
authors.lastname: Trost
authors.forename: Jeanwan
authors.initials: J
authors.lastname: Kang
authors.forename: Robert
authors.initials: R
authors.lastname: Lookstein
authors.forename: Mark
authors.initials: M
authors.lastname: Woodward
authors.forename: Susan
authors.initials: S
authors.lastname: Gustavson
authors.forename: Richard P
authors.initials: RP
authors.lastname: Cambria
authors.forename: Michael R
authors.initials: MR
authors.lastname: Jaff
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Olin
mesh_terms: D000046:Academic Medical Centers; D019540:Area Under Curve; D001783:Blood Flow Velocity; D001900:Boston; D057510:Endovascular Procedures / Q000009:adverse effects* / Q000295:instrumentation*; D006801:Humans; D061330:Multidetector Computed Tomography; D009519:New York City; D011237:Predictive Value of Tests; D012372:ROC Curve; D012008:Recurrence; D012077:Renal Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D012079:Renal Circulation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex
keywords: renal arteries; restenosis; stent; ultrasound