Bile leaks and bile duct strictures caused by accidental injury to the bile duct can occur during any surgical maneuver involving the bile duct. And the current leading cause of bile duct injury is laparoscopic cholecystectomy (LC). Although LC has been shown to be superior to open cholecystectomy by having a shorter hospital stay, lower rate of systemic complications, faster recovery, and better cosmetic outcome, the risk of intraoperative bile duct injury is 2 to 6 times higher with LC compared with open cholecystectomy. Currently, there is no significant change in the incidence of bile duct injuries, even though some authors have reported a decreasing trend. The estimated overall incidence for severe bile duct injuries ranges between 0.25% and 0.74%, while minor bile duct injuries range between 0.1% and 1.7%. I. CLINICAL FEATURES AND DIAGNOSIS The three main clinical features of bile duct injuries include: (1) biliary fistulae, (2) cholestatic peritonitis, and (3) obstructive jaundice with or without acute cholangitis. Different combinations of these clinical features can occur. Most importantly, although some clinical manifestations such as simple jaundice or a well-draining biliary external fistula do not require any emergency management, the presence of infection must be considered an indication for close observation and early treatment of sepsis. When postoperative symptoms appear late, due to slow progression, there may be no overt jaundice or a typical non-jaundiced cholestasis with or without skin itching, as well as recurrent episodes of acute cholangitis. Suspected biliary tract injury is not always easy to diagnose definitively. When mild symptoms such as vague abdominal pain, bloating, low-grade fever, and nausea present early in the post-LC period, some sort of possible complication should be suspected. Initial withdrawal of bile from the abdominal cavity with little or no specific symptoms should also be investigated as soon as possible to finalize the diagnosis and further develop the best treatment plan for each specific patient. In order to develop a treatment plan, direct cholangiography is most important to obtain precise anatomic localization and to classify the injury. In cases of suspected biliary injury, the ERCP technique is not significantly different from routine examination. However, special attention should be paid to the injection of contrast material, aiming for a slow and careful injection to accurately visualize the injury. Large injections of contrast into the biliary tract should be avoided. Small injections and early filling radiographs are also important to show small residual CBD stones. In patients in whom ERCP has failed or in whom intrahepatic bile duct visualization has failed due to proximal bile duct injury, percutaneous transluminal cholangiography (PTC) or MRCP may be used as an alternative. II.TREATMENT In recent years, ERCP has played a crucial role in the management of postoperative biliary complications. The following two major and typical clinical presentations can be treated with the aid of ERCP: (1) biliary intraperitoneal or external fistulae; and (2) obstructive syndromes with cholestasis, cholangitis, and/or jaundice. Diagnostic ERCP is indicated to identify clinically suspected biliary tract injuries, and as much imaging as possible should be obtained. With the exception of type D injuries with complete bile duct transection that require surgical intervention, therapeutic ERCP is increasingly being used as first-line treatment for those postoperative biliary complications for which endoscopic treatment is effective. The vast majority of bile leaks due to minor injuries originate from the stump of the cystic duct. A small number of leaks can also originate from severed Luschka’s duct (a small peripheral bile duct connecting the intrahepatic biliary system to the gallbladder), small subsegments of bile ducts traveling through the gallbladder bed, and segments and subsegments of the vagal branches of the cystic ducts that converge proximally into the CBD. In principle, the treatment of these bile leaks is not different from that of leaks originating in the stump of the cystic duct. Elimination of the pressure gradient on either side of the papilla can be accomplished by endoscopic sphincterotomy (ES) alone, ES and stenting [8] or nasobiliary drainage (NBD) implantation, simple stenting without prior ES or NBD implantation. All methods seem to be equally effective and usually close the bile leak within a week of treatment. The choice of endoscopic treatment remains controversial. If CBD stones are present, ES and lithotripsy are the most logical, with or without combined stenting or NBD implantation. However, each option is subject to certain limitations.ES can be combined with intrinsic near-term or potential long-term complications; stenting requires a second visit to remove the stent and is also subject to blockage or migration; and NBD requires a prolonged hospital stay and is uncomfortable for the patient and occasionally dislodges. Postoperative bile leaks due to minor injuries (type A) are usually effective for endoscopic treatment and have a high success rate. All methods appear to be equally effective in closing bile leaks within a few days. In severe injuries, bile leaks originate from injuries to the CBD or to one of the large branches of the intrahepatic bile duct that form the main confluence (type B). In both cases, ES alone is not sufficient to close the fistula. It is preferable to implant at least one large-diameter plastic stent (10-11.5 Fr) and maintain it for a prolonged period of time in order to adequately divert bile leakage from the injury site. The second purpose of stent implantation is to prevent stenosis that occurs at the site of damage to the bile duct wall. For this purpose, the stent should be left in place for several months to ensure a strong healing process. In the event that a stricture develops at the site of the injury, the implanted stent makes subsequent endoscopic dilatation of the stricture easier. The therapeutic success rate in this case can be 71% to 79%. Biliary stenting has also been successfully used to re-establish continuity of damaged biliary branches at the level of the main confluence of the bile ducts and for bile leaks originating from the vagal bile ducts. In severe injuries of the bile duct with bile leakage, the main therapeutic goal is also to close the fistula and to transform an acute problem into a stabilized state. In any case, the very high effectiveness of endoscopic treatment of this condition has led it to be recognized as the first-line treatment. In the pre-laparoscopic era, the treatment of postoperative biliary strictures was traditionally surgical.The role of ERCP was limited to diagnosis, particularly to determine the level and extent of injury. With the increasing use of ERCP in the evaluation and treatment of acute complications of LC, therapeutic ERCP has been widely used for the treatment of postoperative bile duct stenosis in both the immediate and distant future. Endoscopic treatment is today used as a first-line nonsurgical alternative to surgery, and endoscopic treatment does not preclude the choice of surgery as a remedial treatment for failure of endoscopic treatment. Endoscopic treatment of postoperative biliary strictures is based on the following two steps: crossing the stricture; and dilation of the stricture. The morphologic requirement to allow crossing of the stricture is the continuity of the CBD. In most cases, especially when symptoms persist for a long time after surgery and the stricture is incomplete after access to the CBD via endoscopic cannulation, crossing the stricture becomes the first step in performing dilatation therapy. This maneuver is often more difficult in postoperative stenoses than in neoplastic stenoses because even stenoses that are usually short are often asymmetric. In addition, fibrosis makes the stenosis thin and tight. It is often necessary to apply a thin hydrophilic guidewire (0.021 or 0.018 inch) with a straight or J-shaped tip; these maneuvers require patience, skill, and optimal radiographic monitoring. Changing the patient’s position helps to determine the correct path of the follow-through guidewire radiographically. Pulling the inflated lithotripsy balloon below the stricture helps to straighten the bile duct and adjust the guidewire’s axial orientation. Once through the stricture, the hydrophilic guidewire should be replaced with a stiffer and more stable guidewire for the following dilatation. Stenosis dilatation serves two purposes: firstly, to recanalize the bile duct to restore normal biliary flow, and secondly, to ensure effective dilatation to avoid restenosis in the long term. In the initial phase of endoscopic treatment, only the first aim can be pursued; even though it is very effective in the short term, it is clear that dilatation alone is difficult to maintain good results in long-term follow-up. Nowadays, balloon dilatation is mainly used for the initial treatment with the implantation of one or more plastic stents for continuous supportive dilatation. The role of stent implantation is to maintain long-term patency of the stenosis as the scar deforms and solidifies (from months to years, depending on the treatment plan). Two 10 Fr stents are usually implanted and replaced every three months to avoid cholangitis due to stent blockage, and the stents are left in place for 1 year. In a retrospective study derived from a ten-year (1981-1990) multidisciplinary experience reported by the Amsterdam group, the long-term efficacy of endoscopic versus surgical treatment was compared. Overall, 35 cases underwent surgery (all Roux-en-Y choledocho-jejunostomy), and 66 underwent endoscopic treatment. Patient characteristics, type of initial injury, and level of obstruction did not differ significantly between the two groups. After a mean follow-up of 50 and 42 months for surgical and endoscopic treatment, respectively, 83% of the cases in both groups showed excellent (asymptomatic patients with normal or stable laboratory parameters) or good (simple biliary episodes) results. This important study also shows that endoscopic treatment can be considered at least as effective as surgery in terms of long-term outcome, and that endoscopic treatment has the great advantage that it does not preclude further surgical intervention when needed.The treatment plan used in the group of cases (55 cases) reported by Costamagna et al. consisted of implantation of the maximum number of stents (10 Fr is ideal) possible, as determined by the tension of the stenosis and the internal diameter of the CBD, and the implantation of a stent (10 Fr is ideal). (10 Fr is ideal) were implanted at 3-month intervals as treatment intervals. Treatment was continued until complete resolution of the morphologic stricture on cholangiography.Initial balloon dilatation was required in 40% of cases and was almost always applied during the first treatment. Three patients received a combined application of percutaneous puncture and endoscopic treatment. The mean number of stent placements was 1.7 (1-4) at the first treatment and 3.2 (1-6) at the end of treatment. Disappearance of stenosis could be observed by NBD cholangiography 24-48 hours after stent removal.Early complications (cholangitis in 3 cases, pancreatitis in 1 case) occurred in 4 cases (9%), and stent blockage requiring early replacement occurred in 8 patients (18%). The mean duration of treatment was 12.1±5.3 months (2-24 months). Follow-up was performed every 3 months during the first year and every 6 months after one year and included clinical manifestations, laboratory parameters, and liver ultrasound. Forty-two of the initial 55 patients completed a mean of 49 months of follow-up after the end of treatment and were considered acceptable for evaluation. 10 were excluded, 5 of them because of complete transection of the CBD and the other 5 were treated with self-expanding metallic stents (SEMS). Another 3 cases were not included for different reasons. 2 cases died of unrelated causes during follow-up. Of the remaining 40 patients, there were no symptomatic recurrences due to recurrent bile duct stenosis, and the treatment success rate was 89%. Newly, fully coated retrievable self-expandable metal stents have been reported to be used in the treatment of benign biliary strictures with favorable results, but information from large-sample controlled studies is lacking. Based on published data, endoscopic treatment with combined stent implantation is at least as effective as surgery for severe injuries or strictures of the bile duct. The advantages of endoscopic treatment are simplicity, reproducibility, and minimally invasiveness. Therefore, endoscopic treatment should be considered in the treatment strategy for most patients with severe bile duct injury in hospitals where it is available. For the majority of these patients, endoscopy may be the only treatment needed. Complications can occur either during the initial treatment phase or at the time of stent implantation. Complications occurring during the initial treatment phase are related to ES (acute pancreatitis, retroperitoneal perforation, and hemorrhage), which is usually performed to gain access to the bile ducts. ES-related complications in this situation do not differ in incidence, severity, and management after the occurrence of complications from other more common situations, such as the treatment of CBD stones. Complications during stent implantation are mainly due to stent dysfunction such as blockage, displacement, dislodgement, and obturation. Acute cholangitis is the typical clinical presentation after the onset of stent dysfunction. Cholangitis in this case is usually mild and self-limiting, but still requires immediate endoscopic management, i.e., reestablishment of proper biliary drainage by stent reimplantation. A typical complication of prolonged stenting is the formation of bile sludge and stones above the stricture. This condition can cause cholangitis, but can also be completely asymptomatic. The application of a mesh basket or balloon to remove all stones and bile sludge is essential to avoid early re-obstruction prior to implantation of a new stent. To avoid stone formation, stent replacement every three months should not be prolonged. Therefore, patient compliance is essential in the management of postoperative bile duct stenosis, and patients should be informed of the potential dangers associated with failure to follow a planned regimen on time.