title: Inflammation and delayed endothelization with overlapping drug-eluting stents in a porcine model of in-stent restenosis.
abstract: BACKGROUND
  This study evaluated the inflammatory reaction at the site of overlapping drug-eluting stents (DES) in a porcine model of in-stent restenosis.
  
  
  RESULTS
  Twenty bare metal stents (BMS) (group I; n=10), 20 sirolimus-eluting stents (SES) (group II: n=10), 20 paclitaxel-eluting stent (PES) (group III: n=10), and 10 PES and 10 SES (group IV: n=10) were overlapped in the left anterior descending coronary arteries of 40 pigs. Follow-up coronary angiography and histopathology were performed at 4 weeks after stenting. For the overlapped segments, the minimal luminal diameter at 4 weeks was smaller in group I than in the other groups (1.78+/-0.13 mm, 2.79+/-0.09 mm, 2.90+/-0.04 mm, 2.80+/-0.07 mm, respectively; p<0.001), and the neointimal area (5.51+/-0.58 mm2, 2.38+/-0.53 mm2, 2.07+/-0.37 mm2, 2.39+/-0.58 mm2, respectively; p<0.001) and area stenosis (68.74+/-4.02%, 27.79+/-4.73%, 23.66+/-3.24%, 27.63+/-4.07%, respectively; p<0.001) were higher in group I than in the other groups; however, the inflammatory score was higher in group III than in the other groups (1.80+/-0.42, 2.10+/-0.32, 2.90+/-0.31, 2.50+/-0.52, respectively; p<0.001) and the endothelization score was lower in group III than in the other groups (2.80+/-0.42, 2.30+/-0.67, 1.30+/-0.48, 2.10+/-0.74, respectively; p<0.001).
  
  
  CONCLUSIONS
  Compared with BMS, DES inhibit neointimal hyperplasia, but inflammation and poor endothelization occur at the site of overlapping stents.
authors.affiliation: The Cardiovascular Center of Korea University Anam Hospital, Seoul, Korea.
authors.forename: Sang Yup
authors.initials: SY
authors.lastname: Lim
authors.forename: Myung Ho
authors.initials: MH
authors.lastname: Jeong
authors.forename: Soon Jun
authors.initials: SJ
authors.lastname: Hong
authors.forename: Do Sun
authors.initials: DS
authors.lastname: Lim
authors.forename: Jae Youn
authors.initials: JY
authors.lastname: Moon
authors.forename: Young Joon
authors.initials: YJ
authors.lastname: Hong
authors.forename: Ju Han
authors.initials: JH
authors.lastname: Kim
authors.forename: Youngkeun
authors.initials: Y
authors.lastname: Ahn
authors.forename: Jung Chaee
authors.initials: JC
authors.lastname: Kang
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D023903:Coronary Restenosis / Q000209:etiology* / Q000473:pathology*; D023921:Coronary Stenosis / Q000601:surgery; D003331:Coronary Vessels / Q000473:pathology; D004195:Disease Models, Animal; D054855:Drug-Eluting Stents / Q000009:adverse effects*; D004730:Endothelium, Vascular / Q000473:pathology*; D005260:Female; D006965:Hyperplasia / Q000209:etiology / Q000473:pathology; D007249:Inflammation / Q000209:etiology* / Q000473:pathology*; D017239:Paclitaxel; D020123:Sirolimus; D015607:Stents / Q000009:adverse effects; D013552:Swine; D017539:Tunica Intima / Q000473:pathology
chemical_list: D017239:Paclitaxel; D020123:Sirolimus