title: Stent placement versus angioplasty improves patency of arteriovenous grafts and blood flow of arteriovenous fistulae.
abstract: BACKGROUND
  While endovascular stent placement is the standard of care in most percutaneous coronary and peripheral artery intervention, its role in the salvage of thrombosed and stenotic hemodialysis access remains controversial.
  
  
  METHODS
  We compared the effects of stent versus angioplasty on primary patency rates in the treatment of stenotic arteriovenous fistulae (AVF) and arteriovenous grafts (AVGs). Moreover, we compared access flow (Qa) and urea reduction ratio (URR) between the two groups as a metric of the effect of stent placement versus angioplasty on dialysis delivery.
  
  
  RESULTS
  Cox regression analysis revealed that the primary assisted AVG patency was significantly longer for the stent group compared with angioplasty, with a median survival of 138 versus 61 d, respectively (aHR = 0.17; 95% confidence interval, 0.07 to 0.39; P < 0.001). The primary AVG patency for stent versus angioplasty was 91% versus 80% at 30 d, 69% versus 24% at 90 d, and 25% versus 3% at 180 d, respectively. The primary assisted AVF patency did not differ significantly between the stent and angioplasty groups. In patients dialyzing via AVF, multiple regression analysis revealed that stent placement was associated with improved after intervention peak Qa, 1627.50 ml/min versus 911.00 ml/min (beta = 0.494; P = 0.008), change in Qa from before to after intervention, 643.54 ml/min versus 195.35 ml/min (beta = 0.464; P = 0.012), and change in URR from before to after intervention, 5.85% versus 0.733% (beta = 0.389; P = 0.039).
  
  
  CONCLUSIONS
  Our results suggest that stent placement is associated with improved AVG primary assisted patency and improved AVF blood flow, which may significantly impact on dialysis adequacy.
authors.affiliation: Department of Medicine, Section of Nephrology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53713, USA. mr.chan@hosp.wisc.edu
authors.forename: Micah R
authors.initials: MR
authors.lastname: Chan
authors.forename: Surmeet
authors.initials: S
authors.lastname: Bedi
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Sanchez
authors.forename: Henry N
authors.initials: HN
authors.lastname: Young
authors.forename: Yolanda T
authors.initials: YT
authors.lastname: Becker
authors.forename: Paul S
authors.initials: PS
authors.lastname: Kellerman
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Yevzlin
mesh_terms: D000368:Aged; D017130:Angioplasty / Q000009:adverse effects*; D001166:Arteriovenous Shunt, Surgical / Q000379:methods*; D001783:Blood Flow Velocity; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation; D016022:Case-Control Studies; D005260:Female; D006083:Graft Occlusion, Vascular / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012039:Regional Blood Flow; D006435:Renal Dialysis; D012189:Retrospective Studies; D018570:Risk Assessment; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency