[Application of endoscopic intermuscular dissection in the treatment of rectal tumors]

Rectal tumors, as a common type of gastrointestinal tumor, can be treated through various methods, including endoscopic resection, surgical resection, and radiotherapy. With the in-depth research in the mechanisms of tumors development and the increasing patient demands for quality of life , endoscopic treatment has rapidly advanced due to its advantages of being minimally invasive, promoting faster recovery, and reducing costs. Endoscopic submucosal dissection (ESD), a well-established therapeutic technique, has been widely used for the treatment of precancerous lesions and early-stage tumors in the gastrointestinal tract, as well as for the resection of submucosal tumors such as rectal neuroendocrine tumor. However, ESD faces challenges when dealing with lesions accompanied by severe fibrosis or potential deep submucosal infiltration, leading to difficulties in dissection and the risk of positive vertical margins, which increases the risk of tumor recurrence. The emergence of endoscopic intermuscular dissection (EID) provides a novel approach to address these issues. By dissecting between the inner circular and outer longitudinal muscle layers of the muscularis propria, EID achieves the complete resection of the mucosa, submucosa, and inner circular muscle layer without compromising the integrity of the intestinal wall, thereby resolving the issue of positive vertical margins in histopathological evaluation. The clinical application of EID is still in its early stages. This article reviews the literature to summarize the development and clinical applications of EID technology, providing strategies insights for the minimally invasive endoscopic treatment of rectal tumors.