title: Comparison of access blood flow and venous pressure measurements as predictors of arteriovenous graft thrombosis.
abstract: OBJECTIVE
  The purpose of the present study was to prospectively compare the predictive accuracy of static venous pressure (SVP); dynamic venous pressure (DVP) and access blood flow (ABF) in determining subsequent graft thrombosis and/or failure.
  
  
  METHODS
  This study included 43 patients with functional arteriovenous grafts (AVG's) who underwent monthly seri-al measurements of SVP, DVP and ABF for 3 consecutive months. Patients were then followed for an additional 6 months. The primary end point was graft thrombosis.
  
  
  RESULTS
  Six patients were excluded from the final analysis. Of the 37 patients completing the study, 7 episodes of graft thrombosis occurred within 6 months of follow up. Neither SVP nor DVP exhibited satisfactory sensitivity or specificity for graft thrombosis. Ten patients either began with or developed an ABF < 600 during the 3 months of measurements, but only 5 clotted. delta ABF of >20% provided the best combination of sensitivity (86%) and specificity (90%) for graft thrombosis. In AVG's that have an ABF<600, it is those grafts with falling ABF that appear most likely to clot in the short term.
  
  
  CONCLUSIONS
  The study supports the concept that it is a falling level of access flow rather than the absolute level that is the most potent predictor of graft thrombosis.
authors.affiliation: Department of Medicine, University at Buffalo, NY, USA.
authors.forename: N
authors.initials: N
authors.lastname: Singh
authors.forename: S
authors.initials: S
authors.lastname: Ahmad
authors.forename: J R
authors.initials: JR
authors.lastname: Wienckowski
authors.forename: B M
authors.initials: BM
authors.lastname: Murray
mesh_terms: D000368:Aged; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects; D001783:Blood Flow Velocity; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D005260:Female; D006083:Graft Occlusion, Vascular / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D006435:Renal Dialysis / Q000379:methods; D013927:Thrombosis / Q000175:diagnosis* / Q000209:etiology; D013997:Time Factors; D014690:Venous Pressure