AIM: To demonstrate the outcomes of endoscopic endonasal dacryocystorhinostomy (En-DCR) with an novel lacrimal ostium stent (LOS) which was performed in patients with recurrent epiphora after failed external dacryocystorhinostomy (Ex-DCR) and analyze the causes of failed Ex-DCR. METHODS: From September 2015 and December 2017, the clinic data of 29 cases suffered from recurrent epiphora after failed Ex-DCR was reviewed. The LOS were implanted into the ostium at the end of the revisional surgery. The causes of failed Ex-DCR were analyzed before revisional surgeries. Outcome of revisional surgeries with the new device were evaluated as well. RESULTS: The major causes of failure of the external approach were synechiae formation in the nasal ostium (29/29), followed by inadequate removal of the bony wall (21/29), nasal synechiae formation between lateral wall of nose and middle turbinate (11/29), and the bone opening was not in good location (7/29). The rate of success after revisional surgery was 82.76%. Re-obstruction of the ostiums were found in 5 failed cases. CONCLUSION: Endoscopic approach with a novel LOS may be an effective procedure to manage recurrent epiphora after previous failed Ex-DCR surgery. Synechiae formation in the nasal ostium and inadequate removal of the bony wall were the major causes of failure of Ex-DCR.