title: Oversizing and restenosis with self-expanding stents in iliofemoral arteries.
abstract: OBJECTIVE
  Uncoated self-expanding nitinol stents (NS) are commonly oversized in peripheral arteries. In current practice, 1-mm oversizing is recommended. Yet, oversizing of NS may be associated with increased restenosis. To provide further evidence, NS were implanted in porcine iliofemoral arteries with a stent-to-artery-ratio between 1.0 and 2.3. Besides conventional uncoated NS, a novel self-expanding NS with an antiproliferative titanium-nitride-oxide (TiNOX) coating was tested for safety and efficacy.
  
  
  METHODS
  Ten uncoated NS and six TiNOX-coated NS (5-6 mm) were implanted randomly in the iliofemoral artery of six mini-pigs. After implantation, quantitative angiography (QA) was performed for calculation of artery and minimal luminal diameter. Follow-up was performed by QA and histomorphometry after 5 months.
  
  
  RESULTS
  Stent migration, stent fracture, or thrombus formation were not observed. All stents were patent at follow-up. Based on the location of the stent (iliac/femoral) and the stent-to-artery-ratio, stent segments were divided into "normal-sized" (stent-to-artery-ratio < 1.4, n = 12) and "oversized" (stent-to-artery-ratio ≥ 1.4, n = 9). All stent segments expanded to their near nominal diameter during follow-up. Normal-sized stent segments increased their diameter by 6% and oversized segments by 29%. A significant correlation between oversizing and restenosis by both angiography and histomorphometry was observed. Restenosis rates were similar for uncoated NS and TiNOX-coated NS.
  
  
  CONCLUSIONS
  TiNOX-coated NS are as safe and effective as uncoated NS in the porcine iliofemoral artery. All stents further expand to near their nominal diameter during follow-up. Oversizing is linearly and positively correlated with neointimal proliferation and restenosis, which may not be reduced by TiNOX-coating.
authors: Swiss Cardiovascular Center, University Hospital, Bern, Switzerland. ardan.saguner@usz.ch
authors: Ardan M
authors: AM
authors: Saguner
authors: Tobias
authors: T
authors: Traupe
authors: Lorenz
authors: L
authors: Räber
authors: Nina
authors: N
authors: Hess
authors: Yara
authors: Y
authors: Banz
authors: Arhan R
authors: AR
authors: Saguner
authors: Nicolas
authors: N
authors: Diehm
authors: Otto M
authors: OM
authors: Hess
mesh_terms: D000497:Alloys; D000792:Angiography; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000628:therapy*; D005263:Femoral Artery; D007083:Iliac Artery; D016014:Linear Models; D011897:Random Allocation; D018709:Statistics, Nonparametric; D015607:Stents; D013552:Swine; D013556:Swine, Miniature
chemical_list: D000497:Alloys; C013616:nitinol