ERCP is an acronym for Endoscopic Retrograde Cholangio-Pancreatography, which is abbreviated as ERCP, and translates to mean: Endoscopic Retrograde Cholangiopancreatography. Because the Chinese characters are long and awkward to say, doctors are usually used to saying ERCP, while patients and families are often confused. ERCP is an endoscopic diagnostic technique developed in the 1960s and started in 1973 in China. Initially, it was mainly used to diagnose biliary and pancreatic diseases, but nowadays, due to the rapid improvement of diagnostic technologies such as ultrasound, CT and MRI, the main role of ERCP is not for diagnosis, but for the treatment of biliary and pancreatic diseases, especially bile duct obstruction caused by bile duct stones and biliopancreatic tumors. The endoscope used for ERCP is a duodenoscope, which looks somewhat like a gastroscope, but is a side-view mirror and more difficult to operate. First, the duodenoscope is used to go through the patient’s mouth, esophagus and stomach to reach the duodenum, find the opening of the biliopancreatic duct, that is, the duodenal papilla, then insert the tube into the bile duct and pancreatic duct, inject the contrast agent, clarify the biliopancreatic duct lesions under fluoroscopy, such as bile duct stones and biliopancreatic tumors, and take the corresponding treatment methods. Endoscopic treatment methods for common bile duct stones: 1. Remove the stones: This is the majority of the methods. After using duodenal papillotomy (EST) or dilation (EPBD), the stones are removed with a stone extraction balloon or mesh basket. In some patients with many stones and large diameter, sometimes multiple ERCPs are needed to remove the stones. 2. Biliary drainage: If the patient’s general condition is poor and it is difficult to tolerate the risk of stone extraction, nasobiliary drainage or biliary stent drainage can be used first, and after the patient’s condition improves and stabilizes, ERCP can be used again for stone extraction or surgical treatment. Endoscopic treatment of biliopancreatic tumors (mainly pancreatic head cancer and bile duct cancer): 1. Metal stent placement and drainage (EMBE): It is suitable for patients with advanced tumors who do not want to undergo surgical treatment. Generally, metal stents cannot be removed after being inserted. Metal stents have good drainage effect and long patency time (about 1 year), but they are expensive. 2.Plastic stent placement and drainage (ERBD): It is suitable for temporary short-term drainage of biliopancreatic tumors, to relieve the patient’s jaundice before surgery, and can be removed during surgery. The plastic stent is usually open for 3-6 months. 3, nasobiliary drainage (ENBD): also temporary relief of jaundice, generally not placed for a long time, because the patient is difficult to tolerate. ERCP is not only suitable for patients with general biliopancreatic obstruction, but also for patients with poor general condition, advanced age, and difficulty in tolerating surgery, due to its small trauma and fast recovery, and has been commonly applied in a wide range of hospitals. However, ERCP also has a certain incidence of complications, which can sometimes be fatal. The most common complications are: 1. Acute pancreatitis: the incidence is about 7%. Especially in young people aged less than 60 years, patients who often drink alcohol (pancreatic function is vigorous), and patients with duodenal papillary sphincter insufficiency (SOD). It is also easy to complicate pancreatitis if the operation is prolonged, contrasted with pancreatic ducts, and repeated pancreatic duct intubation. In most cases, pancreatitis is mild, but a few are severe pancreatitis. 2, duodenal papillary bowel perforation: the incidence is about 1%. Mostly, the papilla is cut too large, or the expansion balloon is too large over-expansion, or the stone is too large and tears the papilla. The site due to the special anatomical structure, bile, pancreatic juice, gastrointestinal fluid are very strong corrosive irritation, perforation often causes serious consequences, and more need timely surgical drainage. 3, biliary bleeding: the incidence is about 0.5%. Mostly bleeding at the papillotomy, common in elderly people over 70 years old because of poor vascular elasticity and easy bleeding, or due to the stone embedded in the papilla for a long time, the pressure forms ulcers and bleeding after stone removal.