title: Wall shear stress in the stented superficial femoral artery in peripheral arterial disease.
abstract: OBJECTIVE
  Local changes in wall shear stress (WSS) contribute to vascular wall thickening and subsequent stenosis. Restenosis after stenting is a major concern, especially in the superficial femoral artery (SFA) of patients with peripheral arterial disease (PAD). Local alterations in WSS after stenting might contribute to restenosis/reocclusion. To test the hypothesis that WSS is impaired along the stented SFA segment, we studied the profile of WSS along the femoro-popliteal axis after stent placement in a cross-sectional design.
  
  
  METHODS
  Eighty-seven patients with PAD (89 limbs) were included one day after stenting of the SFA. Flow velocities (peak and mean) and vessel diameter were measured by duplex ultrasound in five predefined segments along the femoro-popliteal axis, at rest and after exercise (30 toe raises); WSS (peak and mean) was calculated from flow velocities, vessel diameter and whole blood viscosity.
  
  
  RESULTS
  WSS progressively declined along the stented segment at rest (peak WSS, p < 0.0001; mean WSS, p < 0.05); after exercise, WSS increased in all segments (all p < 0.001), but, again, progressively declined along the stent (peak WSS, p < 0.0001; mean WSS, p < 0.05). The internal vessel diameter remained unchanged after exercise in the stented and in the non-stented parts of the femoro-popliteal axis (all p > 0.05).
  
  
  CONCLUSIONS
  In PAD patients with SFA stenting WSS is impaired along the femoro-popliteal axis. The consequences of this finding in terms of local effects on the vessel wall that might favor restenosis/reocclusion needs further investigation.
authors: Department of Medicine II, Division of Angiology, Medical University of Vienna, Vienna, Austria.
authors: Oliver
authors: O
authors: Schlager
authors: Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
authors: Sonja
authors: S
authors: Zehetmayer
authors: Department of Medicine II, Division of Angiology, Medical University of Vienna, Vienna, Austria.
authors: Daniela
authors: D
authors: Seidinger
authors: Department of Medicine II, Division of Angiology, Medical University of Vienna, Vienna, Austria.
authors: Bernd
authors: B
authors: van der Loo
authors: Department of Medicine II, Division of Angiology, Medical University of Vienna, Vienna, Austria. Electronic address: renate.koppensteiner@meduniwien.ac.at.
authors: Renate
authors: R
authors: Koppensteiner
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000503:physiopathology*; D033081:Shear Strength / Q000502:physiology*; D015607:Stents / Q000009:adverse effects*; D013314:Stress, Mechanical; D018616:Ultrasonography, Doppler, Duplex
keywords: Blood viscosity; Endovascular treatment; Peripheral arterial disease; Stent; Superficial femoral artery; Wall shear stress