title: Endovascular treatment of hemodialysis arteriovenous fistulas: is immediate post-interventional blood flow a predictor of patency.
abstract: OBJECTIVE
  The purpose of this study was to investigate if the immediate hemodynamic outcome of an endovascular intervention on a dysfunctional hemodialysis arteriovenous fistula is a prognostic factor for primary patency.
  
  
  METHODS
  This was a prospective observational study including 61 consecutive patients with dysfunctional arteriovenous fistulas referred to our endovascular unit. Patients were treated in accordance with institutional standard protocol including immediate pre- and post-interventional blood flow measurements using an intravascular catheter system. The primary endpoint was primary patency at 12 months in patients with an immediate post-interventional blood flow above or below 600 ml/min. Primary patency was estimated using the Kaplan-Meier method with the standard error of the estimate. Multivariate Cox regression analysis was used to study the effect of blood flow and other potential predictor variables.
  
  
  RESULTS
  Post interventional flow did not significantly influence primary patency (p = 0.76). Primary patency was found to be affected by having a history of previous intervention(s) (p = 0.008, hazard ratio 2.9) or low fistula age (P=.038, hazard ratio 0.97 [one-month increase]). Primary patency in group 1 (previous intervention(s)) was 34% ± 13% at 12 months. In group 2 (no previous intervention), primary patency at 12 months was 62% ± 9%.
  
  
  CONCLUSIONS
  The results of this study do not provide scientific support for using the immediate hemodynamic outcome of an intervention as a prognostic factor for primary patency. Low fistula age and a history of previous intervention in particular were found to reduce primary patency significantly.
authors.affiliation: Department of Radiology, Rigshospitalet, Copenhagen, Denmark. thorupheerwagen@gmail.com
authors.forename: Søren T
authors.initials: ST
authors.lastname: Heerwagen
authors.forename: Marc A
authors.initials: MA
authors.lastname: Hansen
authors.forename: Torben V
authors.initials: TV
authors.lastname: Schroeder
authors.forename: Søren D
authors.initials: SD
authors.lastname: Ladefoged
authors.forename: Lars
authors.initials: L
authors.lastname: Lönn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon / Q000009:adverse effects; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D001783:Blood Flow Velocity; D005260:Female; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012039:Regional Blood Flow; D006435:Renal Dialysis; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency