Technical considerations for endoscopic submucosal dissection of a large rectal laterally spreading tumor.

Background and Aims: Endoscopic submucosal dissection (ESD) is an established technique for the management of large colorectal lesions, offering high en bloc and R0 resection rates. Although traction-assisted and tunneling ESD techniques are individually established, each may have limitations in achieving dissection efficiency. We describe important technical considerations in managing large rectal lesions using a combination of both techniques. Methods: A 42-year-old man with mucous stools was found to have a 12-cm rectal laterally spreading tumor, granular type with a dominant nodule. Careful lesion assessment excluded deep submucosal invasion. ESD was performed using both techniques. Results: Initial oral and anal incisions were performed, followed by tunneling dissection. Because of the limited submucosal plane, 2 sequential tractions were applied to enhance exposure. The procedure was completed with en bloc resection, without deep mural injury, and the specimen was successfully retrieved manually to avoid fragmentation. The specimen measured 12 cm, and final pathology showed tubulovillous adenoma, with high-grade dysplasia and R0 resection. Conclusions: The use of tunneling and traction-assisted ESD aids in maintaining an optimal dissection plane and minimizing deep mural injury. Strategic traction placement and gravity-assisted patient positioning are critical for procedural efficiency. Finally, manual specimen extraction can be considered to preserve specimen integrity.