Development of a porcine restenosis model of coronary artery and evaluation by intravascular ultrasound

Objective To develop a porcine restenosis model of coronary artery,and to evaluate it by intravascular ultrasound(IVUS).Methods Nine bare metal stents were implanted into left anterior descendings(LADs) of nine swines [stent/vessel=(1.1-1.2)/1.0].Then 28 days later,the in-stent restenosis were measured by quantity coronary angiography(QCA),IVUS and histomorphology respectively.Results After 28 days five swines were undergone re-examination.QCA showed that the post-stenting vessel diameter increased markedly compared with base vessel diameter [(2.90±0.26)mm vs (2.52±0.31)mm,P=0.001].The follow-up vessel diameter [(1.20±0.77)mm] was diminished markedly compared with the post-stenting vessel diameter(P=0.002),and the percentage of diameter stenosis was(60.2±23.5)%,while the in-stent restenosis rate was 60%.Histomorphometric results showed that the lumen area was diminished remarkably compared with the in-stent areas [(1.29±1.02) mm2 vs(6.04±1.21) mm2,P0.01],and the average percent area of stenosis was(77.9±19.7)%.IVUS analysis yielded similar results [the lumen area(1.67±1.17)mm2 vs(5.85±0.94) mm2,P0.01];the average percent area of stenosis(71.0±23.3)%.Respective area of in-stent,lumen,neointimal and the average percent area of stenosis acquired by IVUS analysis were consistent with histomorphometric results(P0.05).Conclusions A porcine restenosis model of coronary artery was successfully produced in which in-stent restenosis can be evaluated by IVUS in a porcine restenosis model.