title: Five years of vascular access stenosis surveillance by blood flow rate measurements during hemodialysis using the Delta-H method.
abstract: OBJECTIVE
  To report experience over five years of vascular access (VA) stenosis surveillance.
  
  
  METHODS
  We prospectively monitored the blood flow rate (QA) of 145 VA in 131 ESRD (age 62.6 ±13.5 y) patients (pts). QA measurement: within the first hour of the hemodialysis (HD) session by the Delta-H method using the Crit Line III Monitor. All VA with baseline QA < 700 mL/min or decreased > 20% from baseline over time met the positive evaluation (PE) criteria and were referred for angiography (AG) plus elective intervention if stenosis = 50%.
  
  
  RESULTS
  We found 54 cases of PE in 47 VA; the AG was performed in 87% (47/54) cases of PE and most of them (43/47, positive predictive value: 91.5%) showed significant stenosis (mean degree 80.5 ±12.9%). Mean QA increased from 554.7±107.6 mL/min to 977.9 ± 359.9 mL/min just before versus after preventive intervention (P<.001). Without difference when comparing the highest QA reported before stenosis development (889.8 ± 409.5 mL/min) and the QA recorded just post-intervention (P=.18). Kt/V index: improved from 1.43 ± 0.22 to 1.49 ± 0.21 just before versus after intervention (P=.006).
  
  
  CONCLUSIONS
  1) The Delta-H technique is an accurate method for early diagnosis of VA stenosis and is useful in monitoring the hemodynamic effect of elective VA treatment. 2) After preventive intervention for stenosis, functional VA status is restored and HD delivery is improved.
authors.affiliation: Department of Nephrology, Hospital de Mollet, Universitat Oberta de Catalunya-UOC, Barcelona, Spain. 18647rrt@comb.cat
authors.forename: Ramón
authors.initials: R
authors.lastname: Roca-Tey
authors.forename: Rosa
authors.initials: R
authors.lastname: Samon
authors.forename: Omar
authors.initials: O
authors.lastname: Ibrik
authors.forename: Empar
authors.initials: E
authors.lastname: Roda
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: González-Oliva
authors.forename: Román
authors.initials: R
authors.lastname: Martínez-Cercós
authors.forename: Jordi
authors.initials: J
authors.lastname: Viladoms
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D001783:Blood Flow Velocity; D016009:Chi-Square Distribution; D003251:Constriction, Pathologic; D003935:Diagnostic Techniques, Cardiovascular; D042241:Early Diagnosis; D005260:Female; D006083:Graft Occlusion, Vascular / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012039:Regional Blood Flow; D006435:Renal Dialysis; D015203:Reproducibility of Results; D013997:Time Factors; D014654:Vascular Patency