Chronic total occlusion (CTO), a fascinating and dynamic niche in the realm of coronary artery
disease, represents a major technical challenge for interventional cardiologists despite evolution of
better guidewires, devices, experience and techniques. Effective wiring technique is the corner stone to
success of percutaneous coronary intervention (PCI) in CTO. As a guide for guidewire crossing in
CTO, coronary angiography is limited. On the other hand, intravascular ultrasound (IVUS) enhances
the ability to identify coronary anatomy, the exact location of the guidewires within an artery, discriminating
a true lumen from the false lumen before guidewire crossing. Some angiographic features
have been suggested to be predictive of procedural failure, including blunt stump with a side branch at the site of occlusion.
Novel use of IVUS can recognize the optimal entry point and evaluate if a guidewire properly penetrates the proximal
cap of CTO.