title: Restenosis of endovascular stents from stent compression.
abstract: OBJECTIVE
  We sought to determine the basis for restenosis within superficial femoral arteries (SFAs) and hemodialysis conduits treated with balloon-expandable stents.
  
  
  BACKGROUND
  Use of stents within coronary and peripheral vessels continues to increase exponentially. The mechanism of restenosis within stents placed at various vascular sites is not well understood. In particular, the implications of deploying a balloon-expandable stent in a compressible site are not well understood.
  
  
  METHODS
  After the serendipitous detection of stent deformation during intravascular ultrasound (IVUS) examination of a restenosed dialysis fistula, we evaluated a consecutive series of patients with stents placed in compressible vascular sites, including the SFA (six patients) and hemodialysis fistulae (five patients). Clinical, angiographic and IVUS examinations were performed to evaluate mechanisms of restenosis.
  
  
  RESULTS
  Stent compression was identified as the principal cause of restenosis in all dialysis conduits and SFAs. Stent deformity was not reliably identified by angiography; however, IVUS identified compression of two forms: eccentric deformation, implicating two-point compressive force, and complete circumferential encroachment of stent struts around the catheter, suggesting multidirectional compressive force. Despite redilation, secondary restenosis resulting from recurrent compression recurred in most sites.
  
  
  CONCLUSIONS
  Restenosis within balloon-expandable endovascular stents may occur as a result of stent compression, a phenomenon readily detected by IVUS, but often not by angiography. These findings have significant implications for the use of balloon-expandable stents within vascular sites subject to extrinsic compression, such as hemodialysis conduits, the adductor canal segment of the SFA and carotid arteries.
authors.affiliation: Department of Medicine (Cardiology), St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02135, USA.
authors.forename: K
authors.initials: K
authors.lastname: Rosenfield
authors.forename: R
authors.initials: R
authors.lastname: Schainfeld
authors.forename: A
authors.initials: A
authors.lastname: Pieczek
authors.forename: L
authors.initials: L
authors.lastname: Haley
authors.forename: J M
authors.initials: JM
authors.lastname: Isner
mesh_terms: D000368:Aged; D002404:Catheterization; D003251:Constriction, Pathologic; D017023:Coronary Angiography; D005260:Female; D005263:Femoral Artery / Q000473:pathology*; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D006435:Renal Dialysis; D015607:Stents; D018084:Ultrasonography, Interventional; D014654:Vascular Patency