With the development of minimally invasive endoscopic technology, more and more early gastric cancer, precancerous lesions and gastric submucosal diseases can be completely resected endoscopically, eliminating the need for greater surgical trauma. (endoscopic submucosal dissecfion). What is the treatment effect of ESD? ESD treatment for early gastric cancer can achieve high block resection rate (92%~97%) and complete resection rate (73.6%~94.7%), 5-year overall survival rate and 5-year disease survival rate are 96.2%~97.1% and 100% respectively. What is the treatment process of ESD? Determine the extent and depth of the lesion First perform routine endoscopy to understand the site, size, and morphology of the lesion, combined with ultrasound endoscopy, staining, and magnification endoscopy to determine the extent, nature, and depth of infiltration of the lesion. Marking After determining the extent of the lesion, electrocoagulation markings were performed approximately 3~5 mm from the edge of the lesion. For upper gastrointestinal lesions, routine marking was performed; for well-defined lower gastrointestinal lesions, marking was not required. Submucosal injection The injection fluid includes saline, glycerol fructose, sodium hyaluronate, etc. Multi-point submucosal injection is performed lateral to the marker point at the edge of the lesion to lift the lesion and separate it from the muscular layer, which is conducive to complete resection of the lesion by ESD without easily damaging the intrinsic muscular layer and reducing the occurrence of complications such as perforation and bleeding. Incision Part of the mucosa around the lesion is incised along the marker point or the lateral edge of the marker point, and then the entire surrounding mucosa is incised deeper into the submucosa at the incision site. The first incision site is usually the distal end of the lesion, and the flip endoscopic method can be used if excision is difficult. Once bleeding occurs during the incision, the wound is irrigated to clarify the bleeding point and then electrocoagulated to stop the bleeding. Submucosal dissection Before performing dissection, the elevation of the lesion should be judged. Submucosal injections will be gradually absorbed over time, and if necessary, repeated submucosal injections can be performed to maintain adequate elevation of the lesion, and appropriate therapeutic endoscopes and accessories are selected according to the specific circumstances of the lesion. After dissection of the lesion, prophylactic hemostasis should be applied to all visible vessels on the trabecular surface; haemostatic forceps and argon plasma coagulation (APC) should be used to treat possible bleeding sites, and metal clips should be used to close them if necessary; metal clips should be used to close deeper local dissection and fissures in the muscular layer. Intraoperative complication management Intraoperative bleeding can be treated with incisional knife, hemostatic forceps or metal clamps; prophylactic hemostasis of exposed vessels is more important than hemostasis to prevent bleeding; for smaller submucosal vessels, direct electrocoagulation can be performed with various incisional knives or APC; for thicker vessels, electrocoagulation after clamping with hemostatic forceps. Once bleeding occurs during the mucosal peeling process, ice saline can be used to flush the wound, and APC or hemostatic clamp can be used to stop bleeding after clarifying the bleeding point, but APC is often ineffective for arterial bleeding. If the above hemostatic methods are unsuccessful, metal clamps can be used to close the bleeding point, but they often affect the subsequent submucosal peeling operation. In the event of perforation, the lesion can be peeled off after suturing the fissure with a metal clip, or the fissure can be peeled off before suturing the fissure, and the perforation can be caused by small muscle lacerations due to the accumulation of large amounts of gas and high pressure in the GI tract during the long ESD operation. The patient was a 65-year-old male who came to our outpatient clinic with black stool for one week. Gastroscopy suggested mucosal elevation with superficial ulcers in the gastric sinus and ultrasound endoscopy suggested a 2 cm submucosal cystic occupancy. At the same time, CT examination suggested that the patient was combined with gallbladder stones gallbladder. Endoscopic ESD + laparoscopic cholecystectomy was performed under general anesthesia in 2015, 4, 10. Intraoperative icing suggested benign submucosal cholangioma to be drained and chronic calculous cholecystitis. The postoperative recovery is going well. The treatment of this patient completely implemented the concept of minimally invasive, which not only ensured the integrity of lesion removal but also minimized surgical trauma.