Mechanical and Histopathological Comparison between Commercialized and Newly Designed Coronary Bare Metal Stents in a Porcine Coronary Restenosis Model

The aim of this study was to compare the stent designed by Chonnam National University Hospital (designated as CNUH) with commercial cobalt-chromium coronary stent in a porcine coronary overstretch restenosis model. CNUH stent was subjected to mechanical performance tests. Pigs were randomized into two groups in which the coronary arteries (10 pigs, 10 coronaries in each group) had either CNUH stent or control commercial bare metal stent. Histopathologic analysis was assessed at 28 days after stenting. In mechanical performance tests, CNUH stent showed 2.65N, 35.1N, 0.52N, 1.94%, 4.29% in the flat plate radial compression, radial force, 3 point bending, Foreshortening and recoil test, respectively. There was no significant difference in the injury score, internal elastic lamina (IEL), lumen area, neointima area, percent area stenosis, inflammation score and fibrin score between the two groups (1.2±0.35, 4.1±0.41 mm(2), 2.7±0.56 mm(2), 1.6±0.47 mm(2), 36.7±11.2%, 1.2±0.62, 0.2±0.34 in CNUH stent group vs. 1.2±0.38, 3.7±0.64 mm(2), 2.5±0.49 mm(2), 1.5±0.61 mm(2), 36.3±12.17%, 1.1±0.12, 0.4±0.46 in commercial stent group, respectively). In the mechanical performance test, CNUH stent showed the moderated performance under the guideline of FDA. CNUH stent demonstrated similar histological reactions compared with commercial cobalt-chromium stent in a porcine coronary overstretch restenosis model.