title: Validation of computational fluid dynamics-based analysis to evaluate hemodynamic significance of access stenosis.
abstract: OBJECTIVE
  Stenosis in a vascular access circuit is the predominant cause of access dysfunction. Hemodynamic significance of a stenosis identified by angiography in an access circuit is uncertain. This study utilizes computational fluid dynamics (CFD) to model flow through arteriovenous fistula to predict the functional significance of stenosis in vascular access circuits.
  
  
  METHODS
  Three-dimensional models of fistulas were created with a range of clinically relevant stenoses using SolidWorks. Stenoses diameters ranged from 1.0 to 3.0 mm and lengths from 5 to 60 mm within a fistula diameter of 7 mm. CFD analyses were performed using a blood model over a range of blood pressures. Eight patient-specific stenoses were also modeled and analyzed with CFD and the resulting blood flow calculations were validated by comparison with brachial artery flow measured by duplex ultrasound.
  
  
  RESULTS
  Predicted flow rates were derived from CFD analysis of a range of stenoses. These stenoses were modeled by CFD and correlated with the ultrasound measured flow rate through the fistula of eight patients. The calculated flow rate using CFD correlated within 20% of ultrasound measured flow for five of eight patients. The mean difference was 17.2% (ranged from 1.3% to 30.1%).
  
  
  CONCLUSIONS
  CFD analysis-generated flow rate tables provide valuable information to assess the functional significance of stenosis detected during imaging studies. The CFD study can help in determining the clinical relevance of a stenosis in access dysfunction and guide the need for intervention.
authors.affiliation: 2 Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO - USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Hoganson
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Hinkel
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Chen
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Agarwal
authors.forename: Surendra
authors.initials: S
authors.lastname: Shenoy
mesh_terms: D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D001794:Blood Pressure; D003196:Computer Graphics; D003198:Computer Simulation; D006083:Graft Occlusion, Vascular / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D021621:Imaging, Three-Dimensional; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011237:Predictive Value of Tests; D011379:Prognosis; D012039:Regional Blood Flow; D006435:Renal Dialysis; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D018616:Ultrasonography, Doppler, Duplex; D014654:Vascular Patency