1) Perforations during CTO PCI occur in around 5.5% of cases and can involve the septum or epicardium. 2) Most septal perforations require no treatment and are managed with echocardiographic monitoring. 3) Epicardial perforations can be prevented by carefully selecting collaterals for retrograde crossing based on their shape. Treatment involves embolization of the perforation with coils or other materials. 4) Covered stents may also be used to treat epicardial perforations when embolization is not possible or fails.