title: Above and below knee femoropopliteal VIABAHN®.
abstract: OBJECTIVE
  To assess the clinical outcomes of VIABAHN® stent grafts deployed across the knee to those deployed above the knee.
  
  
  BACKGROUND
  The placement of stent-grafts across the knee joint and extending into the distal popliteal artery has been avoided due to a perceived higher risk of stent fractures, restenosis, and thrombosis due to the unique hemodynamic forces in this region.
  
  
  METHODS
  A retrospective evaluation was conducted of 114 patients in 127 limbs. Patients were divided into two groups based on the location of the distal end of the deployed VIABAHN® stent: above knee (AK) (n=89) in which the VIABAHN® implant ended at or above the femoral condyles and below the knee (BK) (n=38) with extension of the graft into the below knee popliteal segment. Study end points were loss of primary, assisted, and secondary patency.
  
  
  RESULTS
  One year primary, assisted, and secondary patency rates in the AK versus BK group were 67.7% vs. 47.2% (P=0.0092), 77.1% vs. 53.7% (P=0.0022), and 86.3% vs. 59.8% (P=0.0035), respectively. Univariate analysis demonstrated an increased relative risk of a primary [RR=2.07 (P=0.001)], assisted [RR=2.34 (P=0.002)], or secondary events [RR=2.98 (P=0.002)] in patients when the stent was placed below the femoral condyles. Major amputations occurred in 10% of AK and 34% of BK patients (P=0.002).
  
  
  CONCLUSIONS
  VIABAHN® stent grafts have a significantly lower clinical patency and higher rates of amputation when they extend across the knee joint.
authors.affiliation: Department of Radiology, Stony Brook University Hospital, Stony Brook, New York.
authors.forename: Christopher
authors.initials: C
authors.lastname: Shackles
authors.forename: John H
authors.initials: JH
authors.lastname: Rundback
authors.forename: Kevin
authors.initials: K
authors.lastname: Herman
authors.forename: Yitzchak
authors.initials: Y
authors.lastname: David
authors.forename: Ravit
authors.initials: R
authors.lastname: Barkarma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000503:physiopathology / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D005263:Femoral Artery / Q000503:physiopathology / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011150:Popliteal Artery / Q000503:physiopathology / Q000601:surgery*; D011474:Prosthesis Design; D012189:Retrospective Studies; D016896:Treatment Outcome; D014654:Vascular Patency
keywords: VIABAHN®; critical limb ischemia; popliteal