Background Edge dissections after coronary stent implantation are associated with increased short-term risk of major adverse cardiovascular events.The incidence and outcome of edge dissections after coronary stent implantation were reportedly different using different imaging techniques.We used optical coherence tomography (OCT) to assess the incidence,morphological findings and related factors of edge dissections after drug-eluting stent (DES) implantation.Methods Totally 42 patients with 43 de novo lesions in 43 native arteries undergoing DES implantation with OCT imaging were enrolled in this study.Results Nine edge dissections were detected in 43 arteries after DES implantation.There were four morphological patterns of stent edge dissections indentified in this study:(1) superficial intimal tears (n=3),(2) subintimal dissections (n=4),(3) split of media (n=1),(4) disruption of the fibrotic cap of plaque (n=1).Stent edge expansion and stent expansion were both higher in the group with dissections than those in the group without dissections (1.682±0.425 vs.1.229±0.285,P=0.0290; 1.507±0.445 vs.1.174±0.265,P=0.0072).Conclusions The incidence of stent edge dissections detected by OCT was 21％.Stent edge dissection is related with stent edge expansion and stent expansion.