title: Arterial kink and damage in normal segments of the superficial femoral and popliteal arteries abutting nitinol stents--a common cause of late occlusion and restenosis? A single-center experience.
abstract: OBJECTIVE
  To identify a new angiographic parameter associated with poor short- and long-term outcomes with nitinol stenting in the larger infrainguinal arteries.
  
  
  BACKGROUND
  Nitinol stents have proven to be useful and safe, but imperfect, tools for treating claudication and limb-threatening ischemia. Primary and secondary patency in superficial femoral artery (SFA) occlusions treated with nitinol stents are up to 80% at 1 year, but restenosis is between 40-50% at 2 years. The causes of SFA and popliteal restenosis remain unclear. Stent fracture has been implicated in some cases of restenosis, but this is clearly the minority. Chronic mechanical trauma to the arteries caused by native vessel-stent interaction, intensified by limb motion over time, appears to be a more plausible explanation.
  
  
  METHODS
  Presented here are 2 cases of restenosis apparently caused by acute and chronic trauma to the native vessel from interaction of the artery with the ends of relatively rigid nitinol stent systems.
  
  
  RESULTS
  The source of some future restenotic and occlusive events are not apparent using routine angiography techniques.
  
  
  CONCLUSIONS
  The additional step of an on-table leg bend test at 80-90 degrees will allow the interventionalist to visualize many cases of negative interaction between the native artery and the stents that will occur during routine movement. This allows the operator to potentially avoid stent-induced arterial trauma.
authors.affiliation: Peninsula Regional Medical Center, Salisbury, Maryland, USA. cardiodude@aol.com
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Arena
mesh_terms: D000368:Aged; D000497:Alloys; D015901:Angiography, Digital Subtraction; D001157:Arterial Occlusive Diseases / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D005263:Femoral Artery; D006083:Graft Occlusion, Vascular / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D011150:Popliteal Artery; D011475:Prosthesis Failure; D015607:Stents; D013997:Time Factors; D018084:Ultrasonography, Interventional
chemical_list: D000497:Alloys; C013616:nitinol