“…Although there has been no definite consensus on the safety of retrograde PCI for coronary CTO so far, the paucity of published reports has shown the complications of this technique [12,21,22]. In this study, the retrograde approach does not seem to be a completely safe procedure, and we experienced several cases of unexpected complications, such as a dissection or acute thrombosis of the collateral-donor artery, which usually do not happen during the conventional antegrade approach.…”