Endoscopic suturing promotes healing of mucosal defects after gastric endoscopic submucosal dissection: endoscopic and histologic analyses in in vivo porcine models (with video)

Background and Aims: Endoscopic suturing of mucosal defects after endoscopic submucosal dissection (ESD) is expected to prevent postoperative adverse events. We aimed to endoscopically and histologically evaluate the healing process of post-ESD mucosal defects closed with endoscopic hand suturing (EHS) in in vivo porcine models. Methods: Twelve mucosal defects (2 cm in size) were created in 2 pigs (6 defects per pig). Initially, 2 defects were created: one was closed with EHS (sutured group) and the other was kept open (control group). On postoperative days (PODs) 7 and 14, 2 additional defects were created in each session, and they were treated in the same manner as in the initial procedure. On POD 21, the entire stomach, with the 6 lesion sites, was extracted for histologic evaluation after endoscopic observation. Results: Endoscopically, all sutured sites remained closed in all sessions (PODs 7, 14, and 21). Histologically, on POD 14, the epithelium and muscularis mucosae were appropriately connected. The mucosae were covered with the epithelium without inversion of the mucosal edge in the sutured group, whereas the ulcer bed was exposed in the control group. Furthermore, the degree of neovascularity and fibroblasts in the submucosa was smaller in the sutured group than that in the control group. Conclusions: Our findings suggest that endoscopic suturing promotes healing of post-ESD mucosal defects histologically in in vivo porcine models. Thus, endoscopic mucosal closure after ESD might be clinically useful for the prevention of delayed perforation/bleeding if secure suturing is performed endoscopically.