title: Efficacy of color flow duplex imaging for proximal upper extremity venous outflow obstruction in hemodialysis patients.
abstract: OBJECTIVE
  The efficacy of color flow duplex imaging (CFDI) in detecting proximal upper extremity venous outflow obstruction in hemodialysis patients was compared with that of traditional contrast venography.
  
  
  METHODS
  From 1993 through 1997, all hemodialysis patients who were evaluated for upper extremity venous outflow obstruction of the axillary, subclavian, or brachiocephalic veins with both CFDI and venography were identified. Medical history, hemodialysis access procedures, and indications for imaging were reviewed. The diagnostic accuracy of CFDI was compared with that of venography for proximal venous outflow obstruction, including focal stricture, partial obstruction, or complete occlusion.
  
  
  RESULTS
  Sixty upper extremities in 42 hemodialysis patients were imaged with both CFDI and venography. Previous ipsilateral intravenous dialysis catheters had been present in 33 (55%) of the extremities imaged; current catheters were present in 16 (27%) of the extremities imaged; and 28 (67%) of the extremities imaged had a current ipsilateral arteriovenous (AV) shunt. Five (8%) of the 60 duplex scans were nondiagnostic because of artifact from intravenous dialysis catheters (3) or incomplete visualization of the subclavian or brachiocephalic veins (2) and were excluded from further analysis. In the remaining 55 duplex scans, proximal venous outflow obstruction was found in 18 (33%), compared with 21 (38%) identified by means of venography (P = not significant [NS]). Overall sensitivity, specificity, positive predictive value, and negative predictive value for CFDI were 81%, 97%, 94%, and 89%, respectively.
  
  
  CONCLUSIONS
  CFDI is a reliable means of detecting proximal upper extremity venous outflow obstruction and should replace contrast venography as the initial imaging study in hemodialysis patients.
authors.affiliation: Division of Vascular Surgery, Department of Surgery, University of North Carolina, Chapel Hill, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Passman
authors.forename: E
authors.initials: E
authors.lastname: Criado
authors.forename: M A
authors.initials: MA
authors.lastname: Farber
authors.forename: G L
authors.initials: GL
authors.lastname: Risley
authors.forename: C B
authors.initials: CB
authors.lastname: Burnham
authors.forename: W A
authors.initials: WA
authors.lastname: Marston
authors.forename: S J
authors.initials: SJ
authors.lastname: Burnham
authors.forename: B A
authors.initials: BA
authors.lastname: Keagy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001132:Arm; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D008875:Middle Aged; D010690:Phlebography; D011237:Predictive Value of Tests; D006435:Renal Dialysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color; D018616:Ultrasonography, Doppler, Duplex; D014652:Vascular Diseases / Q000000981:diagnostic imaging*