title: Inflow stenoses in dysfunctional hemodialysis access fistulae and grafts.
abstract: BACKGROUND
  The aim of the study is to prospectively determine the incidence of inflow stenoses in dysfunctional hemodialysis access arteriovenous fistulae (AVFs) and grafts (AVGs).
  
  
  METHODS
  Contrast-enhanced magnetic resonance angiography (CE-MRA) was performed of 66 dysfunctional AVFs and 35 AVGs in 56 men and 45 women (mean age, 62 years; age range, 31 to 86 years). Complete inflow (from the subclavian artery), shunt region, and complete outflow (including subclavian vein) were shown at CE-MRA. In addition to standard digital subtraction angiography (DSA) of the shunt region and outflow, DSA of the complete inflow was obtained through access catheterization of all cases in which CE-MRA showed an inflow stenosis. Vascular stenosis is defined as greater than 50% decrease in luminal diameter compared with an uninvolved vascular segment located adjacent to the stenosis. Endovascular intervention of stenoses was performed in connection with DSA.
  
  
  RESULTS
  CE-MRA showed 19 arterial stenoses in 14 patients (14%). DSA confirmed 18 of these lesions in 13 patients and showed no additional inflow lesions. Of the 13 patients, 7 patients had arterial stenoses only and 6 patients had accompanying stenoses in the shunt region and/or outflow. Referral criteria for the 13 patients to undergo access evaluation had been decreased flow rates (9 patients), steal symptoms (2 patients), and insufficient access maturation (2 patients). Access flow of the 9 patients with a low-flow access improved from 477 +/- 74 mL/min to 825 +/- 199 mL/min after angioplasty. One patient with steal symptoms became symptom free after angioplasty. Endovascular intervention in 3 patients proved to be unsuccessful.
  
  
  CONCLUSIONS
  Inflow stenoses are not uncommon in dysfunctional hemodialysis access shunts. We suggest that radiological evaluation comprise assessment of the complete arterial inflow.
authors.affiliation: Department of Radiology, Catharina Hospital, Eindhoven, The Netherlands. lemduijm@hotmail.com
authors.forename: Lucien E M
authors.initials: LE
authors.lastname: Duijm
authors.forename: Ylian S
authors.initials: YS
authors.lastname: Liem
authors.forename: Rob H H
authors.initials: RH
authors.lastname: van der Rijt
authors.forename: Ferenc J
authors.initials: FJ
authors.lastname: Nobrega
authors.forename: Harrie C M
authors.initials: HC
authors.lastname: van den Bosch
authors.forename: Petra
authors.initials: P
authors.lastname: Douwes-Draaijer
authors.forename: Philippe W M
authors.initials: PW
authors.lastname: Cuypers
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Tielbeek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D002408:Catheters, Indwelling; D003251:Constriction, Pathologic / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012039:Regional Blood Flow; D006435:Renal Dialysis; D013348:Subclavian Artery / Q000473:pathology*