Comparisons of the Mucosal Healing Process between Flat and Protruded Type after Endoscopic Submucosal Dissection for Gastric Neoplasms

Background/Aims: The mucosal healing process after endoscopic submucosal dissection (ESD) is mostly scarring change (flat type), but a protruded lesion is occasionally found. We investigated the factors influencing the mucosal healing process, such as the flat and protruded types. Methods: A total of 2,096 ESD cases were performed from February 2005 to December 2013, and 1,757 underwent follow-up endoscopy after 3 months to check the healing type of the ulceration. We retrospectively reviewed the medical charts to analyze demographic, endoscopic, and pathological findings between the 2 groups. Results: Forty-eight cases were of the protruded type and 1,709 were of the flat type. In univariate analysis, the protruded type was found more in the antrum, anterior wall, and greater curvature (p < 0.001). In protruded types, the Helicobacter pylori (H. pylori) infection rate was lower (p < 0.017), the mean length of ESD specimen was shorter (p < 0.012), the fibrosis rate was lower (p < 0.033), and the mean number of hot biopsy and clips during ESD were less (p < 0.008 and p < 0.001 respectively). Conclusions: The healing type of mucosal ulceration after ESD seemed to be influenced by location, specimen size, and the presence of an H. pylori infection.