title: Effect of multilevel sequential stenosis on lower extremity arterial duplex scanning.
abstract: BACKGROUND
  The sensitivity of lower extremity arterial duplex scanning in detecting a > 50% stenosis may be decreased in extremities with multilevel sequential stenosis.
  
  
  METHODS
  The results of lower extremity arterial duplex scanning of the common femoral, upper and lower superficial femoral, above- and below-knee popliteal arteries, and tibioperoneal trunk in 80 extremities of 44 patients were compared to those of arteriography. Thirty-one arterial segments in 27 extremities had a > 50% stenosis. The stenoses were categorized as first order (first or only stenotic segment in the extremity, n = 23) and second order (stenosis occurring distal to a > 50% stenosis, n = 4, or occlusion, n = 4).
  
  
  RESULTS
  The sensitivity, specificity, and positive predictive values of duplex scan detection of a > 50% arterial stenosis or occlusion were 86%, 96%, and 67% for the common femoral artery; 95%, 98%, and 95% for the upper superficial femoral artery; 97%, 90%, and 88%, for the lower superficial femoral artery; 84%, 90%, and 87% for the above-knee popliteal artery; 47%, 98%, and 90% for the below-knee popliteal artery; and 25%, 100%, and 100% for the tibioperoneal trunk. Duplex scanning detected 18 (78%) of the 23 first-order stenoses compared to only 1 (13%) of the 8 second-order stenoses in limbs with multilevel sequential disease (P < 0.01). The peak systolic velocity at the stenotic site was significantly higher for first-order (mean +/- SD 168 +/- 54 cm/s) compared to second-order (38 +/- 13 cm/s) stenoses (P < 0.00002).
  
  
  CONCLUSIONS
  Duplex scanning was highly sensitive in detecting lower extremity first-order stenoses. Low peak systolic velocities at second-order stenoses of limbs with multilevel sequential disease significantly decreased the sensitivity of duplex scanning.
authors.affiliation: Department of Surgery, University of Louisville School of Medicine, Kentucky 40292, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Bergamini
authors.forename: C M
authors.initials: CM
authors.lastname: Tatum
authors.forename: C
authors.initials: C
authors.lastname: Marshall
authors.forename: B
authors.initials: B
authors.lastname: Hall-Disselkamp
authors.forename: J D
authors.initials: JD
authors.lastname: Richardson
mesh_terms: D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001783:Blood Flow Velocity; D016009:Chi-Square Distribution; D005263:Femoral Artery / Q000000981:diagnostic imaging*; D006801:Humans; D007866:Leg / Q000098:blood supply / Q000000981:diagnostic imaging; D015588:Observer Variation; D011150:Popliteal Artery / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011859:Radiography; D012680:Sensitivity and Specificity; D016909:Tibial Arteries / Q000000981:diagnostic imaging*; D018616:Ultrasonography, Doppler, Duplex