Stent-based nitric oxide delivery reducing neointimal proliferation in a porcine carotid overstretch injury model.
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.
Hou
Dongming
D
Indiana University School of Medicine, Indianapolis, Indiana, USA. dmhou@iupui.edu
Narciso
Hugh
H
Kamdar
Kirti
K
Zhang
Ping
P
Barclay
Bruce
B
March
Keith L
KL
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
D020099:Coated Materials, Biocompatible; D012828:Silicones; D009569:Nitric Oxide; D011138:Polytetrafluoroethylene