Laser-excimer Versus High-pressure Dilation to Treat Under-expansion of the Stent

The laser-excimer technology could be an essential tool to correct the under-expansion of the stent once it has been implanted unless severe calcification. The investigators propose a study that serves as proof of concept for this technology (laser Excimer) used according to its intended use in this specific substrate of coronary lesions. (stent under-expansion without severe underlying calcification).The laser-excimer technology achieves a greater minimum luminal area when treating an infra-expanded stent, when compared with the results obtained with the simple dilatation at high or very high pressure.