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Abstract: TH-PO763

Comparison of FTM Risk Score versus Surgical Opinion for Primary and Secondary AV-Fistula Creations

Session Information

Category: Dialysis

  • 603 Hemodialysis: Vascular Access


  • Winkler, Eliot Johnathon, University Health Network, Toronto, Ontario, Canada
  • Suleiman, Sami, Toronto General Hospital, Toronto, Ontario, Canada
  • Gudsoorkar, Prakash, None, Toronto, Ontario, Canada
  • Lok, Charmaine E., Toronto General Hospital, Toronto, Ontario, Canada

Arteriovenous fistulas (AVF) continue to have high failure-to mature (FTM) rates. A validated FTM Risk Score may help stratify patients by FTM risk to improve VA decision making. It is unclear how well the FTM Risk Score correlates with surgical opinion. We aimed to describe the FTM risks of primary and secondary AVFs and elucidate the relationship between the FTM Risk Score and surigcial opinion for these two subgroups.


Data was propsectively collected between 2006-2014 during VA clinics where 5 surgeons assessed patients for potential VA creation at an academic hospital. The FTM Score was determined for each patient ("FTM Score") while surgeons independently evaluated the patient's likelhood of AVF maturation as: Excellent, Good, Marginal, or Poor ("Surgeon Score"), which corrleated to the FTM Risk Score e.g. FTM Risk of "low" corresponded to Surgeon Score "Excellent". Descriptive statistics categorized the surgeon and clinician risk scores as low, moderate, high, or very high risk;overall Fleiss Kappa statistics were calculated (SPSS, V. 23).


There were 355 primary AVF, 42 secondary AVF with both Scores collected and verified. Overall, the Risk Scores were: low risk-26%; moderate risk-41.5%; high risk-30.3%; very high risk-2.2%. The Risk Score had a Kappa agreement of 0.78 with the Surgeon Score ( p<0.001). The categories of risks were similar (Table 1). The FTM Score and Surgeon Score had Kappas of 0.72 (primary) and 0.75 (secondary). Mean FTM Risk Score was 3.11 (primary) and 3.45 (secondary); mean Surgeon Score was 3.22 ( primary and 3.64 (secondary).


The distribution of AVF failure risk was similar between the FTM Risk Score and Surgeon's clinical evaluation. However, the agreeement improved with secondary AVFs, suggesting that more clinical information from prior AVF outcomes improve clinical predication. The AVF outcomes according to FTM Risk Score and Surgeon Score are the focus of ongoing research.

Primary AVF Access   Secondary AVF Access   
Risk of FTM (%)% (n=355)Surgeon Evaluation% (n=355)Risk of FTM (%)% (n=42)Surgeon Evaluation% (n=42)
Very High3.4Poor3.1Very High0Poor0
Overall Kappa0.72*  Overall Kappa0.75*  


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