title: Duplex ultrasound for the prediction of vascular events associated with arteriovenous fistulas in hemodialysis patients.
abstract: OBJECTIVE
  To determine if duplex ultrasound (US) for arteriovenous fistulas (AVFs) can predict vascular events (VEs; thrombosis and stenosis).
  
  
  METHODS
  Duplex US was performed for vascular access evaluation in 2557 maintenance hemodialysis (HD) patients between October 1, 2013 and March 31, 2016. Of these patients, 2184 patients were finally included in this study. AVF dysfunction was assessed using the brachial artery blood flow volume (Qa; mL/min), arterial blood flow resistance index (RI), and residual diameter of the fistula vein (RD; mm). Proximal, midpoint, and distal aspects of the fistulas were measured. The baseline measurements were the US assessments, and the endpoint was VEs requiring vascular access intervention therapy or vascular surgery. Associations of US findings and VEs were assessed with receiver operating characteristic curve analysis, log-rank analysis, and multivariate Cox hazard models.
  
  
  RESULTS
  The mean Qa was 772.8 ± 441.4 mL/min; RI, 0.56 ± 0.1; and RD, 2.37 ± 1.0 mm. The optimal Qa cut-off point was calculated as 581.5 mL/min, RI cut-off as 0.56, and RD cut-off as 1.85 mm. VEs were more frequent in patients with a Qa <581.5 mL/min than in those with a Qa >581.5 mL/min (p<0.001). In multivariate analysis, Qa, ferritin, transferrin saturation, and warfarin use were significantly associated with VEs.
  
  
  CONCLUSIONS
  US evaluation of AVFs in HD patients is a simple method to predict the risks of thrombosis and fistula dysfunction. Qa, ferritin, transferrin saturation, and warfarin use might be associated with VEs.
authors.affiliation: Zenjinkai Group, Internal Medicine, Yokohama-Daiichi Hospital, Yokohama, Kanagawa - Japan.|Department of Epidemiology and Public Health, Graduate School of Medicine, Yokohama City University, Yokohama, Kanagawa - Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Ishii
authors.affiliation: Zenjinkai Group, Department of Clinical Engineering, Surveillance Echo Team, Yokohama-Daiichi Hospital, Yokohama, Kanagawa - Japan.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Zenjinkai Group, Department of Clinical Engineering, Surveillance Echo Team, Yokohama-Daiichi Hospital, Yokohama, Kanagawa - Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Zenjinkai Group, Department of Clinical Engineering, Surveillance Echo Team, Yokohama-Daiichi Hospital, Yokohama, Kanagawa - Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Ohmori
authors.affiliation: Zenjinkai Group, Department of Clinical Engineering, Surveillance Echo Team, Yokohama-Daiichi Hospital, Yokohama, Kanagawa - Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Masai
authors.affiliation: Zenjinkai Group, Vascular Access Center, Yokohama-Daiichi Hospital, Yokohama, Kanagawa - Japan.
authors.forename: Naru
authors.initials: N
authors.lastname: Sasagawa
authors.affiliation: Zenjinkai Group, Internal Medicine, Yokohama-Daiichi Hospital, Yokohama, Kanagawa - Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Ohyama
mesh_terms: D000368:Aged; D019540:Area Under Curve; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D001783:Blood Flow Velocity; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D053208:Kaplan-Meier Estimate; D007674:Kidney Diseases / Q000175:diagnosis / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012372:ROC Curve; D012039:Regional Blood Flow; D006435:Renal Dialysis; D012086:Reoperation; D012307:Risk Factors; D013927:Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D014654:Vascular Patency