title: Enhanced flow velocity after stenting of renal arteries is associated with decreased renal function.
abstract: BACKGROUND
  Atherosclerotic renal artery stenosis (RAS) is frequently treated by angioplasty and stent placement. Duplex sonography is an established noninvasive technique for patient follow-up. There is lack of evidence that routine monitoring of asymptomatic patients with stable blood pressure is needed.
  
  
  METHODS
  Renal duplex sonography was performed in 64 patients who had received percutaneous angioplasty and stenting of an atherosclerotic RAS. Duplex sonographic diagnosis was made by a combination of direct flow measurement in the renal artery and evaluation of intrarenal resistive indices. Renal function was determined by serum creatinine and calculated glomerular filtration rate (GFR).
  
  
  RESULTS
  With a mean follow-up of 28 months after angioplasty, a flow velocity of >2.0 m/s was detected within the stented arteries in 11/64 patients. While the initial blood pressure and GFR as well as the influence of angioplasty on these parameters were not different, the decrease in renal function over time was significantly higher in patients with flow enhancement (annual GFR decrease, 8.0 ml/min vs. 0.8 ml/min; p < 0.05).
  
  
  CONCLUSIONS
  Follow-up duplex sonography in patients after renal artery stenting detected an unexpectedly high rate of in-stent restenosis associated with enhanced loss of renal function. Routine duplex sonographic follow-up may detect patients at risk of more rapidly declining renal function.
authors.affiliation: Medical Department IV, University of the Saarland, Homburg/Saar, Germany. inmgir@uniklinik-saarland.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Girndt
authors.forename: Harald
authors.initials: H
authors.lastname: Kaul
authors.forename: Carla
authors.initials: C
authors.lastname: Maute
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kramann
authors.forename: Hans
authors.initials: H
authors.lastname: Köhler
authors.forename: Michael
authors.initials: M
authors.lastname: Uder
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty; D001783:Blood Flow Velocity; D003251:Constriction, Pathologic / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D015607:Stents / Q000009:adverse effects; D018616:Ultrasonography, Doppler, Duplex