Endoscopic removal of gastrointestinal lesions by using third space endoscopy techniques

The submucosal space, also known as the “third space,” is located between the intact mucosal flap and the muscularis propria layer of the gastrointestinal tract. Endoscopists can use this space to perform interventions in the muscularis propria layer or breech it to enter the mediastinum or the peritoneal cavity without full thickness perforation. This updated narrative review summarizes the evidence that analyses indications and outcomes of tunnelling techniques for the treatment of above-mentioned lesions.