Supplementary Material for: Factors related to delayed adverse events of endoscopic submucosal dissection in the duodenum

Introduction: Endoscopic submucosal dissection for duodenal neoplasms (D-ESD) is considered a technically demanding procedure regarding the high risk of delayed adverse events. Data regarding optimal managements of ulcers after D-ESD are lacking. Methods: A retrospective analysis was performed on consecutive 145 cases of D-ESD for superficial non-ampullary duodenal epithelial tumors at a single referral center. Factors related to delayed adverse events and the healing process of ulcers after D-ESD were analyzed. Results: Complete ulcer suture after D-ESD was performed in 128 cases (88%). Two delayed perforation occurred among cases with incomplete suture. Delayed bleeding occurred in 8 cases (6%) within three weeks. The ulcer closure rate at second-look endoscopy was significantly low among cases with delayed bleeding (12.5% vs 75%, P=0.001). The bleeding rate before second-look endoscopy was significantly high among patients who did not have complete ulcer closure after D-ESD (0.8% vs 12%, P=0.036). The ratio of lesions located in the 2nd oral-Vater was significantly low among ulcers re-opened at second-look endoscopy (38% vs 14%, P=0.044). Proton-pump inhibitors (PPI) were administered for a median of seven weeks (range 1-8 weeks). At three weeks, active ulcer stages were observed in a few cases, and healing or scarring was observed in most cases. Conclusions: Complete ulcer suture was related to decreased risk of delayed adverse events after D-ESD. From the bleeding period and healing process of D-ESD ulcers, the minimum required length of PPI may be three weeks after D-ESD.