Background The retrograde approach allows to significantly increase the success rate of coronary chronic total occlusion (CTO) percutaneous intervention (PCI).Epicardial collateral channels (CCs) remain an essential channel for retro-recanalization.But paucity of data in this area limits the use of epicardial CCs for retrograde canalization.The present study was to explore the feasibility and significance of coronary epicardial collaterals for the retrograde approach treatment of coronary CTO.Methods We retrospectively analyzed 347 CTO cases which the retrograde approach was attempted after reviewing the coronary angiograms of 1290 patients.And there were 89 retrograde approach PCI cases applying epicardial CCs.We collected the clinical and angiography data of those patents for analyzing the safety and usefulness of this technology.Results The study consisted of 347 CTO PCI.Mean age was 60.8±10.4 and 60.3±10.2 years in epicardial CCs and septal CCs groups respectively.The total retrograde success rate was 79.8％.The success rate of retrograde approach applying epicardial CCs was not lower (82.0％ vs.79.1％,P=0.646) than that in cases applying septal CCs.There were 8 epicardial CCs injury cases (9.0％) and 3 cases resulted in cardiac tamponade and required emergency pericardiocentesis.Coils were used for all of them with success.No patients were dead in retrograde approach applying epicardial CCS.Conclusions Coronary epicardial collaterals can be used as an access for the retrograde approach in the percutaneous treatment of CTO,which is relative feasible,and has a high success rate.Epicardial CCs injury can be safety as long as it is treated timely.E