title: Patterns of blood flow as a predictor of maturation of arteriovenous fistula for haemodialysis.
abstract: OBJECTIVE
  A palpable "thrill" is traditionally associated with success following arteriovenous fistula (AVF) surgery. A thrill typically characterizes turbulent flow and this is a paradox as turbulence is a driver of neointimal hyperplasia. Spiral laminar flow (SLF) has been described as normal and protective pattern of flow in native arteries and is associated with superior patency in bypass grafts that generate it. The aim of this study was to define the pattern of flow within AVFs immediately post-operatively and at follow-up to assess maturation.
  
  
  METHODS
  Doppler ultrasound was used immediately post-operatively and at follow-up (6 weeks). Blood flow was assessed as SLF or non-SLF. Two blinded qualified observers analysed the images. Patients were followed up for 6 months. Maturation was statistically analysed against the type of flow.
  
  
  RESULTS
  Sequential patients having AVF surgery (n=56) were assessed: 46 (82%) patients had a thrill, 3 patients had no flow and 7 patients had pulsatile flow without a palpable thrill. SLF was present in 80% of those with a thrill but not in any without a thrill (p<0.0001). At follow-up (n=51) 41, patients had a matured AVF (80%), of which 76% had SLF immediately post-operatively. Only one patient with SLF failed to mature. In the non-SLF group 5 of the 15 AVFs failed to mature (66%; p<0.005).
  
  
  CONCLUSIONS
  SLF was strongly supportive of successful fistula maturation. A "thrill" was characteristic of spiral rather than turbulence. The mechanism of this apparent beneficial effect of this pattern of flow requires further investigation.
authors.affiliation: 1 Department of Renal Surgery, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Trust, Birmingham - UK.
authors.forename: Yazin
authors.initials: Y
authors.lastname: Marie
authors.forename: Alison
authors.initials: A
authors.lastname: Guy
authors.forename: Karen
authors.initials: K
authors.lastname: Tullett
authors.forename: Hari
authors.initials: H
authors.lastname: Krishnan
authors.forename: Robert G
authors.initials: RG
authors.lastname: Jones
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Inston
mesh_terms: D000328:Adult; D000368:Aged; D001166:Arteriovenous Shunt, Surgical; D001783:Blood Flow Velocity; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D006435:Renal Dialysis; D013997:Time Factors; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler