title: A scoring system (DISTAL) for predicting failure of snuffbox arteriovenous fistulas.
abstract: OBJECTIVE
  A first fistula failing will lead to serious morbidity in a proportion of patients. Snuffbox fistulas have the advantage of proximal vessel preservation, and although several factors have been associated with failure, the relative importance of these factors combined and their clinical applicability is unknown. The aim of this study was to determine the relative importance of risk factors for snuffbox fistula failure and create a simple scoring system to aid fistula placement decision making.
  
  
  METHODS
  218 consecutive patients were examined using Cox regression analysis to determine risk factors for failure. Primary patency was used as the endpoint.
  
  
  RESULTS
  Diabetes, IHD, Stroke, Two snuffbox procedures, Age > 70 and Less than 2.0 mm vein (DISTAL, maximum score 6) were significant predictors of primary patency failure. There was a clear decrease in primary patency with increasing DISTAL score (log rank χ(2) = 30.3, DF = 5, P < 0.001). Performing snuffbox procedures on patients with a score ≤ 3 would give a 23% reduction in the number of failures within two months for a 12% reduction in the number of patients offered snuffbox procedures.
  
  
  CONCLUSIONS
  The DISTAL scoring system could give large improvements in primary patency for the snuffbox fistula if the results can be validated in other datasets.
authors.affiliation: Department of Vascular Surgery, Morriston Hospital, Swansea, UK.
authors.forename: C P
authors.initials: CP
authors.lastname: Twine
authors.forename: M
authors.initials: M
authors.lastname: Haidermota
authors.forename: J D
authors.initials: JD
authors.lastname: Woolgar
authors.forename: C P
authors.initials: CP
authors.lastname: Gibbons
authors.forename: C G
authors.initials: CG
authors.lastname: Davies
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001166:Arteriovenous Shunt, Surgical; D016121:Brachiocephalic Veins / Q000502:physiology / Q000601:surgery*; D003657:Decision Making; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D017534:Radial Artery / Q000502:physiology / Q000601:surgery*; D006435:Renal Dialysis / Q000379:methods; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013927:Thrombosis / Q000453:epidemiology; D017211:Treatment Failure; D006113:United Kingdom / Q000453:epidemiology; D014654:Vascular Patency; D055815:Young Adult