group 1 and in 1 patient (2.4%) in group 2, and the difference was not statistically significant (P = 0.16). The functional success rate was 81% in group 1 and 95.1% in group 2. The difference between the 2 groups is statistically significant (P = 0.04).
DISCUSSIONThe most important reason for surgical failure in E-DCR is the closure of the bone window due to abnormal wound healing. Different instruments have been used to modify this abnormal wound healing, but their efficacy has not been clearly demonstrated. 3,4 Studies have suggested that different factors that may be effective in the development of granulation such as bare bone tissue. It has been claimed that covering the bone window with the flaps created, thus preventing the development of granulation and fibrosis through primary wound healing. 5 Some authors suggested that flap-sparing surgery is not superior to conventional surgery and only prolongs the duration of operation. 6 In this study, observed that the frequency of granulation development was significantly lower in the flap surgery group, but functional success rates was higher.Different flap techniques such as U flap, U and D flap, U and F flap, L flap, free mucosal flap have been reported in the literature. [7][8][9][10] Whatever technique is used, the main purpose is to create flaps that surround and stabilize the bone window as much as possible. In the U and L flap techniques, tissue loss is frequently observed while creating and repositioning the flap, causing technical difficulties for the surgeon. 10 In the U and D flap techniques, repositioning the nasal mucosa flap, whose base is formed above, against gravity creates serious difficulties. 9 In this study, unlike other techniques in the literature, modified inverted U flap mucosa-sparing surgery was performed. In this way, there is no risk of tissue loss, and the flaps are designed in accordance with gravity and lacrimal system drainage, thus providing easy stabilization. In addition, granulation tissue formation was significantly reduced compared with conventional surgery and the success rate was significantly increased.In conclusion, modified inverted U flap mucosa-protected E-DCR achieves higher functional success rates and causes less granulation than flapless surgery. In addition, owing to this method, similar success rates to external DCR can be achieved. However, the main point that should not be forgotten here is that this surgery takes a long time to learn and requires serious experience.