Esd medically refers to endoscopic submucosal dissection, which is a surgical procedure performed through an endoscope. Endoscopic submucosal dissection belongs to a kind of minimally invasive surgery, which is mainly applied to the treatment of huge flat polyps in the digestive tract, early gastric wall tumors, esophageal tumors, colon tumors and other diseases. This approach is less damaging to the patient’s body, with fast postoperative recovery and fewer after-effects. The principle of endoscopic submucosal dissection is that the lesion to be removed is firstly evaluated through endoscopic observation, and then the lesion is separated from normal tissues by drugs and electric knife, and then the lesion tissues are pinched out with the clip attached to the endoscope to achieve the therapeutic effect. This procedure requires a trip to the hospital for formal operation by a physician.