title: Wall shear stress measurement using phase contrast magnetic resonance imaging with phase contrast magnetic resonance angiography in arteriovenous polytetrafluoroethylene grafts.
abstract: OBJECTIVE
  The purpose of the present article was to determine the changes in luminal vessel area, blood flow, and wall shear stress in both the inflow artery and the venous stenosis of arteriovenous polytetrafluoroethylene (PTFE) grafts.
  
  
  METHODS
  Polytetrafluoroethylene grafts were placed from the carotid artery to the ipsilateral jugular vein in 8 castrated juvenile male pigs. Contrast-enhanced magnetic resonance angiography (MRA) with cine phase-contrast magnetic resonance imaging (MRI) was performed 2 weeks after graft placement.
  
  
  RESULTS
  The mean wall shear stress at the venous stenosis was 4 times higher than the control vein, while the inflow artery was only 2-fold higher. By day 14, venous stenosis had formed, which was characterized by narrowed area and elevated blood flow.
  
  
  CONCLUSIONS
  By day 14, there is venous stenosis formation in porcine arteriovenous PTFE grafts with increased shear stress with decreased area when compared to control vein.
authors.affiliation: Department of Radiology, Division of Vascular and Interventional Radiology, Mayo Clinic College of Medicine, 200 First Street SW, Alfred 6460, Rochester, MN 55902, USA. Misra.sanjay@mayo.edu
authors.forename: Sanjay
authors.initials: S
authors.lastname: Misra
authors.forename: Alex A
authors.initials: AA
authors.lastname: Fu
authors.forename: Khamal D
authors.initials: KD
authors.lastname: Misra
authors.forename: James F
authors.initials: JF
authors.lastname: Glockner
authors.forename: Debabrata
authors.initials: D
authors.lastname: Mukhopadhyay
mesh_terms: D000818:Animals; D001166:Arteriovenous Shunt, Surgical / Q000295:instrumentation*; D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D002339:Carotid Arteries / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D002369:Castration; D003251:Constriction, Pathologic; D019544:Equipment Failure Analysis; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D007601:Jugular Veins / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D018810:Magnetic Resonance Angiography; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008422:Materials Testing; D023421:Models, Animal; D011138:Polytetrafluoroethylene; D011474:Prosthesis Design; D012039:Regional Blood Flow; D006435:Renal Dialysis; D013314:Stress, Mechanical; D013552:Swine; D013997:Time Factors; D014654:Vascular Patency
chemical_list: D011138:Polytetrafluoroethylene