Guidance of stenting by IVUS has been proposed as a method to reduce restenosis rates, because lumen and stent dimensions can be accurately determined by intravascular ultrasound (IVUS). However, randomized studies investigating this strategy have yielded inconsistent results. Therefore, the investigators hypothesized that the potential advantages of IVUS guidance would be most apparent in Chronic Total Occlusion (CTO) intervention and try to evaluate the impact of IVUS-guided chronic total occlusion intervention with drug-eluting stents on mid-term angiographic, IVUS and clinical outcomes.