Internal and external bile duct drainage via ERCP is the most common treatment for biliary obstruction, and has become the first-line treatment for common bile duct stones. For cancerous obstructive jaundice (ENBD) or bile duct stenting can be used as preoperative measures to reduce yellowing, and for those who cannot be operated, bile duct stents can also be placed to relieve clinical symptoms and improve the quality of life. The results of 506 cases of biliary obstruction with duodenoscopic biliary drainage from October 2003 to December 2007 in our hospital are summarized below. Pan Xiaoping, Department of Interventional Vascular Surgery, Wuhai People’s Hospital Clinical data and methods I. General data There were 506 cases in this group, 304 males and 202 females, age 34-83 years old, average 61.42 years old. All patients had preoperative symptoms of different degrees of biliary obstruction such as abdominal pain, xanthogranuloma, fever, etc., along with changes in liver function. The diagnosis of benign disease was confirmed by ERCP examination combined with ultrasound, CT or MRI in 329 cases, including 240 cases of hepatobiliary stones and 89 cases of benign strictures; 177 cases of malignant disease, including 44 cases of cholangiocarcinoma of the hilar region, 87 cases of cholangiocarcinoma of the common bile duct, 25 cases of cancer of the head of the pancreas and 21 cases of cancer of the jugular abdomen. Among them, there were 33 cases of acute obstructive purulent cholangitis and 37 cases of biliary pancreatitis caused by various reasons. Thirty-two cases were accompanied by serious medical diseases, including cardiac arrhythmias, chronic obstructive pulmonary disease, and cerebrovascular accidents. The etiology of biliary obstruction and endoscopic drainage modalities are shown in Table 1.Table 1 Etiology of biliary obstruction and endoscopic drainage modalities in 506 cases Disease Number of cases ENBD ERBD EMBE Hepatobiliary stones and inflammatory strictures 329 297 32 – Primary hilar cholangiocarcinoma 44 18 26 – Common bile duct cancer 87 30 54 3 Pancreatic head cancer 25 5 17 3 Jugular belly cancer 21 5 11 5 Total 506 355 140 11 II. METHODS 1. Instruments and apparatus Olympus TJF-230 electronic duodenoscope was used, and the nasobiliary duct was a polyvinyl chloride tube ( F7x240cm), and the internal stent was a polyvinyl chloride tube with single or multiple flap barbs at both ends (F8.5×5-8cm). The metal stent was a nickel-titanium alloy. 2. Methods Liver and kidney function and blood amylase were routinely measured before endoscopic treatment. Local anesthesia with lidocaine in the throat, intramuscular injection of Valium 5-10 mg and intravenous injection of Antispasmodicin 20-40 mg were performed before surgery. heart rate, blood pressure and electrocardiogram were monitored intraoperatively. For patients with severe medical disease and severe acute cholangitis, a person was assigned to monitor the vital signs. Endoscopic retrograde cholangiopancreatography (ERCP) is performed first, and the drainage method is decided according to the site of obstruction and the nature of the lesion after the imaging. If the stone is too large to be removed through the nipple, a mechanical lithotripsy basket is used. After lithotripsy, a nasobiliary drainage tube is placed for drainage. (2) For severe septic cholangitis, transitional drainage is performed by direct endoscopic naso-biliary drainage (ENBD), which is placed at the upper proximal end of the obstruction site according to the imaging results. After exiting the endoscope, bile is directly extracted from the nasobiliary duct; EST or stone extraction is performed after the condition improves and the jaundice subsides. For severe septic cholangitis caused by papillary embedded stones, immediate needle knife incision and drainage followed by nasobiliary drainage is performed. (3) For benign bile duct strictures, endoscopic retrograde biliary drainage (ERBD) or transitional drainage is performed after dilating the strictured segment with a dilator placed along the guidewire, and then ERBD is placed after one week of observation of the transitional drainage by ENBD.(4) For bile duct malignancy (caused by its own lesion or compression by surrounding malignant lesions), dilatation of the strictured segment with a dilator is performed after ERBD or endoscopic metal biliary endoprothesis (EMBE) is performed. The choice of drainage tube is usually based on the nature and location of the lesion and the length of the biliary stenosis as determined by the ERCP results. After endoscopic treatment, vital signs, abdominal signs and drainage were observed, and blood amylase was rechecked 3 h after the procedure. After the endoscopic treatment, the patient should be fasted for 1-2 days, and after the amylase is normalized, the patient can eat liquid food or semi-liquid food. For those with intraoperative pancreatic duct development and those with increased amylase, drugs to inhibit pancreatic enzyme secretion can be given to prevent and treat acute pancreatitis. The efficacy of the treatment of septic cholangitis is satisfactory if the body temperature decreases within 1 to 2 days and the symptoms disappear completely within a week; the efficacy of the treatment of infection prevention is satisfactory if no infection symptoms occur within 2 weeks and no jaundice occurs [1]; the criterion for successful endoscopic biliary drainage is the relief of all biliary obstruction symptoms, including the relief of abdominal pain and jaundice. The criteria for successful endoscopic biliary drainage were relief of all biliary obstruction symptoms, including relief of abdominal pain, reduction of xanthogranuloma, and decrease in body temperature. The results showed that 481 of 506 cases were successfully drained, with a success rate of 95.1%, and the symptoms of biliary obstruction were relieved, including reduction of jaundice, decrease in body temperature and pain. 33 patients with combined acute septic cholangitis had jaundice, fever and abdominal pain resolved within 24 h after ENBD treatment. 240 patients with common bile duct stones were treated with transnasal cholangiography three days after surgery, and 225 patients had bile duct stones removed once, while 15 patients had stones remaining. In 89 cases of papillitis and benign stenosis of the lower part of the common bile duct, the stenosis was lifted and jaundice was eliminated after duodenal papillotomy. 37 cases of cholestatic pancreatitis were treated with ENBD, and in 32 cases, the blood and urine amylase rapidly decreased to normal, and the disease was controlled and discharged after comprehensive treatment, while 4 cases formed severe pancreatitis and 1 case died. Among 25 patients with pancreatic head cancer, 4 cases were treated with double stent drainage of pancreatic duct and bile duct with obvious effect. 19 of 25 patients with failed intubation were treated with Percutaneous transhepatic choledochal drainage PTCD. 11 patients with malignant stenosis of bile duct were treated with EMBE, a large amount of thick black bile came out from the stent, jaundice decreased and the quality of life improved. The average drainage time for the whole group was 43.3 days (l-193 days), including ENBD 4.1 days and ERBD 95.5 days. Discussion Endoscopic biliary lithotripsy and internal drainage by placement of internal stents and external drainage by placement of nasobiliary ducts are the basic methods of endoscopic treatment for benign and malignant obstructive diseases of the biliary tract, and endoscopic biliary decompression can be accomplished by external drainage by placement of nasobiliary ducts and internal drainage by placement of internal stents. Nasobiliary duct placement is mainly used for biliary flushing, repeated cholangiography or treatment of patients with refractory stones, decompression of acute septic cholangitis, prevention of cholangitis and prevention of stone impaction in patients after diagnostic ERCP, and is called prophylactic drainage. The placement of internal and external drains through the duodenum has become the new standard of care for biliary diseases. Practice has shown that effective bile duct decompression in patients with malignant biliary obstruction can not only improve quality of life and prolong survival, but also create opportunities for chemotherapy, radiotherapy or radical surgery for some patients [2]. In the past, biliary obstruction was mostly treated by surgical drainage. In recent years, with the improvement of endoscopic technology and the experience of endoscopists, the success rate of endoscopy in the treatment of biliary tract diseases has been greatly improved. Endoscopic treatment can be performed without anesthesia and abdomen, which has the advantages of less trauma, less pain, faster recovery, shorter hospital stay, and positive efficacy, fully reflecting the superiority of “minimally invasive treatment”, and many patients avoid surgery. Transendoscopic bile duct drainage includes internal drainage and external drainage, the former we use ERBD and EMBE, the latter we use ENBD, which has achieved better results. Compared with surgical biliary short-circuit surgery and percutaneous hepatic percutaneous biliary drainage, transendoscopic biliary drainage is more widely used, with minimal complications and mortality, minimal physiological disturbance to the patient, and low physical demands on the patient. For biliary obstruction, a guidewire should be used to select the bile duct with the widest drainage range; due to the uniqueness of the site, not only is the surgical resection rate of hilar tumors extremely low, but also palliative surgery such as biliary short-circuiting is extremely difficult; percutaneous percutaneous biliary drainage (PTCD) still has certain invasiveness and more complications, mainly causing water-electrolyte loss and disorders, requiring hospitalization for supplementation and drainage tube care, which makes it difficult for patients to be discharged. It is difficult for patients to be discharged from the hospital, and PTCD is often used as a short term palliative care measure, mostly in preparation for surgery. ENBD is generally used for transient drainage [2.3], such as decompression of acute septic cholangitis, prevention of cholangitis and stone impaction after bile duct obstruction and diagnostic ERCP, and treatment of traumatic biliary fistula, etc. It can often be the first choice, and then be changed to ERBD or EMBE after the treatment plan is determined, which is called transitional drainage. The advantages are convenient and reliable, cheap domestic nasobiliary tube, clear bile drainage, flushing, imaging, drug injection when necessary, and easy to remove the drainage tube, but the disadvantage is that there is bile loss, affecting the fluid-hydropower balance, inconvenient life for patients, and careful use in severe varices. The main problem is the blockage of the lumen, generally the blockage rate of plastic stent is 20%-30% within 3 months, 60%-70% within 6 months, and the average patency period is 3-5 months, so it should be replaced immediately once the jaundice recurrence occurs. In contrast, 11 cases of EMBE, currently placed for more than 6 months, have not been reoccluded, which is a significant advantage over ERBD. However, the experience is less and needs to be further accumulated. We believe that (1) the use of endoscopic internal and external bile duct drainage for acute purulent cholangitis, obstructive jaundice from various causes, biliary fistula and biliary pancreatitis can improve the systemic condition of patients with obstructive jaundice and reduce mortality. (2) Endoscopic bile duct drainage can maximize the survival period of patients with malignant obstruction without surgical indications, improve their quality of life during survival, and create conditions for further chemotherapy and radiotherapy. (3) Nasal bile duct is inexpensive and can be used as temporary drainage, which can clarify the bile drainage flow and be used for flushing, imaging and drug injection when necessary, and it is convenient to remove the drainage tube, which has its superiority. (4) ERBD has no bile loss problem and is more often used for palliative reduction of yellowing in patients with malignant biliary obstruction who have lost the chance of surgery. (5) EMBE for malignant obstruction of the common bile duct is effective in reducing yellowness without the problem of early reobstruction.