title: Stent-based nitric oxide delivery reducing neointimal proliferation in a porcine carotid overstretch injury model.
abstract: BACKGROUND
  The effects of nitric acid (NO) on vessel response to injury include the inhibition of platelet adhesion, platelet aggregation, leukocyte adhesion and smooth muscle cell proliferation. Releasing NO from a stent might reduce the clinical problem of restenosis. The present study was designed to examine whether an NO-eluting covered stent can prevent neointimal formation in a porcine carotid overstretch injury model.
  
  
  METHODS
  The interior of a self-expanding polytetrafluoroethylene (ePTFE)-covered aSpire stent was coated with silicone, which contained 23.6 microg or 54.5 microg sodium nitroprusside (SNP, NO-releasing compound). The stent was implanted into carotid artery. Six pigs were implanted with stents, one high-dose SNP and one uncoated control, following balloon overstretch injury of the carotid artery with a balloon-to-artery ratio of 1.3:1.
  
  
  RESULTS
  No local or systemic toxicity was evidenced in the six pigs after carotid artery implantation with either low- or high-dose stents within a week. At day 28, the mean intimal thickness was 0.12 +/- 0.05 mm for NO-eluting stents and 0.43 +/- 0.09 mm for uncoated stents (p = 0.008). The mean neointimal area was reduced from 2.40 +/- 0.39 mm2 for control stents to 0.49 +/- 0.16 mm2 for NO-eluting stents (p < 0.0001), which resulted in a 24% reduction of angiographic vessel narrowing.
  
  
  CONCLUSIONS
  The NO-eluting ePTFE-covered stent is feasible and effectively reduces in-stent neointimal hyperplasia at 28 days in a porcine carotid overstretch model.
authors.affiliation: Indiana University School of Medicine, Indianapolis, Indiana, USA. dmhou@iupui.edu
authors.forename: Dongming
authors.initials: D
authors.lastname: Hou
authors.forename: Hugh
authors.initials: H
authors.lastname: Narciso
authors.forename: Kirti
authors.initials: K
authors.lastname: Kamdar
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Bruce
authors.initials: B
authors.lastname: Barclay
authors.forename: Keith L
authors.initials: KL
authors.lastname: March
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D020212:Carotid Artery Injuries / Q000473:pathology*; D016893:Carotid Stenosis / Q000209:etiology / Q000517:prevention & control*; D020099:Coated Materials, Biocompatible; D004195:Disease Models, Animal; D006965:Hyperplasia / Q000473:pathology / Q000517:prevention & control; D009569:Nitric Oxide / Q000008:administration & dosage* / Q000494:pharmacology*; D011138:Polytetrafluoroethylene; D012828:Silicones; D015607:Stents; D013552:Swine; D017539:Tunica Intima / Q000187:drug effects / Q000473:pathology
chemical_list: D020099:Coated Materials, Biocompatible; D012828:Silicones; D009569:Nitric Oxide; D011138:Polytetrafluoroethylene