title: Reliability of ultrasound duplex for detection of hemodynamically significant stenosis in hemodialysis access.
abstract: OBJECTIVE
  This study aims to evaluate the accuracy of AVF and AVG duplex ultrasound (US) compared to angiographic findings in patients with suspected failing dialysis access.
  
  
  METHODS
  From July 2008 to December 2010, US was performed on 35 hemodialysis patients with 51 vascular accesses having clinical feature or dialysis parameter suspicious of access problem. Peak systolic velocity ratio of ≥2 was the criteria for diagnosing stenosis ≥50%. Fistulogram was performed in all these patients. Results of US and fistulogram were compared using Kappa and Receiver Operator Characteristic (ROC) analyses.
  
  
  RESULTS
  In 51 accesses (35 AVF, 16 AVG), US diagnosed significant stenosis in 45 accesses according to the criteria and angiogram confirmed 44 significant stenoses. In AVF lesions, Kappa was 0.533 with 93.3% sensitivity and 60% specificity for US whereas in AVG lesions, Kappa was 0.636 with 100% sensitivity and 50% specificity. Overall Kappa value of 0.56 meant fair to good agreement. ROC demonstrated area under the curve being 0.79 for all cases and was significant (p = 0.016). Using the ≥50% criteria for stenosis diagnosed by US yielded the best sensitivity (95.5%) and specificity (57.1%).
  
  
  CONCLUSIONS
  Duplex ultrasound study, using ≥50% criteria, is a sensitive tool for stenosis detection in patients with suspected failing AVF and AVG.
authors: Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Ashvin
authors: A
authors: Vardza Raju
authors: Kyin
authors: K
authors: Kyin May
authors: Min
authors: M
authors: Htet Zaw
authors: Carolina
authors: C
authors: Capistrano Canlas
authors: Mary
authors: M
authors: Hannah Seah
authors: Catherine
authors: C
authors: Menil Serrano
authors: Mikael
authors: M
authors: Hartman
authors: Pei
authors: P
authors: Ho
keywords: AVF; angiogram; hemodialysis; stenosis; ultrasound
references: Semin Intervent Radiol. 2004 Jun;21(2):95-103
references: 21331115
references: J Ultrasound Med. 2014 Jul;33(7):1321-32
references: 24958422
references: Nephrol Nurs J. 2006 Sep-Oct;33(5):487-8
references: 17044433
references: Nephrology (Carlton). 2010 Apr;15(3):300-6
references: 20470298
references: Vasc Med. 2006 Nov;11(3):183-200
references: 17288127
references: Ann Vasc Dis. 2011;4(2):87-92
references: 23555435
references: Surg Today. 2006;36(9):775-8
references: 16937279
references: J Vasc Surg. 2005 Oct;42(4):739-46
references: 16242563
references: Am J Kidney Dis. 2006 Jul;48(1):98-105
references: 16797391
references: J Vasc Surg. 2009 Sep;50(3):594-9
references: 19595550
references: Ann Acad Med Singap. 2007 Mar;36(3):157-60
references: 17450258