ASGE guideline for endoscopic full-thickness resection and submucosal tunnel endoscopic resection.

With the development of reliable endoscopic closure techniques and tools, endoscopic full-thickness resection (EFTR) is emerging as a therapeutic option for the treatment of subepithelial tumors and epithelial neoplasia with significant fibrosis. EFTR may be categorized as "exposed" and "nonexposed." In exposed EFTR, the full-thickness resection is undertaken with a tunneled or nontunneled technique, with subsequent closure of the defect. In nonexposed EFTR, a secure serosa-to-serosa apposition is achieved before full-thickness resection of the isolated lesion. This document reviews current techniques and devices used for EFTR and reviews clinical applications and outcomes.