Successful closing of duodenal ulcer after endoscopic submucosal dissection with over-the-scope clip to prevent delayed perforation.

Closure of post-endoscopic submucosal dissection (ESD) duodenal artificial ulcer is not common in the clinical setting. We consider that post-ESD ulcer closure by an over-the-scope-clip (OTSC) method is one of the most effective ways to prevent delayed perforation. We report here two cases of mucosal duodenal cancer in a 65-year-old woman and in a 78-year-old man. Pathological examinations of the resected specimens revealed well-differentiated adenocarcinomas. In these two clinical cases, we successfully carried out complete closures of post-ESD duodenal ulcer using OTSC without any complications.