Laparoscopic intragastric surgery (LIGS) has become more widely established in Japan as a therapy for early gastric cancers and some types of submucosal gastric tumors. However, there have been some technical difficulties with the original method of LIGS. Certain complicated procedures to access the gastric lumen are required, along with repair of the gastric wall after endoluminal procedures. Using a 5-mm radially expandable sleeve (RES) for the working ports in LIGS, it becomes easier to establish access to the gastric lumen, and repair of the port sites on the gastric wall is not required. Using RES makes LIGS a simpler, less invasive procedure.