Third space endoscopy refers to a group of endoscopic procedures performed in the "third space," which is the potential space inside the GI tract's wall. This usually entails working in the organ wall's submucosal layer. Per Oral Endoscopic Myotomy (POEM) and Endoscopic Submucosal Dissection are the two most common procedures performed in the third space. Zenker's Diverticulotomy (ZPOEM), endoscopic gastric pyloromyotomy (GPOEM), submucosal tunnelling endoscopic resection (STER), and tunnelling recanalization of the oesophagus are all examples of third space endoscopy.
These highly specialized techniques include submucosal tunneling endoscopic resection (STER) and full- thickness endoscopic resection (FTER) of Gl-based tumors.