Clinical applications of submucosal endoscopy

Purpose of Review: Submucosal endoscopy with mucosal flap (SEMF), a new diagnostic and therapeutic intervention of flexible endoscopy, has been examined from the perspective of developmental laboratory work, procedural details, and results of early clinical experiences. Recent Findings: Diagnostic natural orifice translumenal endoscopic surgery (NOTES) procedures, endolumenal achalasia myotomy, and submucosal tumor excision have been clinically performed with a SEMF method. The outcomes of these procedures were equivalent to standard surgery but with reduced morbidity. Some were accomplished under conscious sedation within the endoscopy unit. Summary: The SEMF procedure was originally developed to provide safe access to the peritoneal cavity for NOTES procedures. In the SEMF method, the submucosal layer is endoscopically tunneled and the resultant space is used as an endoscopic path into deeper layers of the gut wall and an offset exit to the peritoneal cavity. Key to the method is the overlying mucosa which serves as a sealant flap minimizing the risk of soiling a body cavity with lumenal contents and the ease by which the entry point into the submucosal working space can be closed. Positive outcomes of the early SEMF clinical experiences validate that the submucosa can be transformed into a promising novel working space for flexible endoscopy.