ASGE Endoscopic Learning Library. This edition of the ASGE Endoscopic Learning Library features the use of endoscopic retrograde cholangiogram in management of benign biliary diseases. The topics covered include management of common bile duct stones, surgical biliary complications, benign biliary strictures, primary sclerosing cholangitis, and sphincter of Autie dysfunction. Each topic will include a review of the latest knowledge, controversies and video demonstrations of the endoscopic procedure. Common pitfalls and difficulties frequently encountered will also be discussed. Management of Common Bile Duct Stones. In this chapter, an overview on the methods of enlarging the biliary sphincter, CBD stone extraction, management of giant CBD stones, and intrahepatic ductose stones will be given. Methods of Enlarging the Biliary Sphincter. The Technique of Endoscopic Sphincterotomy. After initial canalation, the access to the common bile duct is maintained with the guide wire. The sphincterotome is passed to the papilla, and the cutting wire is bowed to allow contact with the roof under minimal tension. Excessive tension on the wire may lead to coagulum formation and result in an uncontrolled cut. The incision should be made in a stepwise manner, towards the 11 and 12 o'clock. And the upper extent of the sphincterotomy is confined to the transverse mucosal fold, which is the junction between the duodenal wall and the intraduodenal portion of the ampullae avatare. This video demonstrates the technique of endoscopic sphincterotomy. The sphincterotome was first passed to the papillary orifice. It was then bowed to allow contact with the roof under minimal tension, and the incision was made in a stepwise manner towards the 11 and 12 o'clock. Both the tension on the wire and the cutting direction may need to be varied so as to allow optimal contact of the wire in the appropriate angle. The upper extent of the sphincterotomy is confined to the transverse mucosal fold. The technique of endoscopic balloon dilation. After initial canalation, the balloon catheter is passed over the guide wire and positioned across the papilla. Depending on the size of stones, the balloon is inflated to a size ranging between 6 to 20 millimeters. Dilation is confirmed by observing the disappearance of wasting, and the balloon inflation is maintained for 60 seconds. And the technique has the potential benefit of preserving the function of the sphincter of audi. This video demonstrates the technique of endoscopic balloon dilation. After CBD axis is gained, the balloon catheter is introduced into the CBD and centered at the papilla. The balloon is then inflated to a size matching that of the CBD stones, which ranges from 6 to 20 millimeters. Disappearance of wasting is observed, and the dilation is maintained for 60 seconds. The CBD stones can then be retrieved. Endoscopic sphincterotomy versus endoscopic balloon dilation. In comparing these two methods, various meta-analyses have already shown similar success and complication rates. While bleeding occurs more frequently after endoscopic sphincterotomy, post-ERCP pancreatitis happens more often in those undergoing balloon dilation. It has also been shown that endoscopic balloon dilation is effective in removing small to moderate-sized stones. However, it is associated with more frequent use of the mechanical lithotriptor. Hence the exact role of EBD remains controversial, as it is more risky in terms of pancreatitis. But it seems to be an acceptable option for coagulopathic patients. Endoscopic sphincterotomy with balloon dilation. Limited sphincterotomy plus balloon dilation has been shown to be a safe and effective alternative when compared to endoscopic sphincterotomy in gaining common bile duct access. Both methods have been shown to have similar rates of stone removal, and this includes stones that are larger than 15 millimeters in size. Further, there are no significant differences in the rates of complications, which includes post-procedural pancreatitis and bleeding. The technique of endoscopic sphincterotomy with balloon dilation first involves a limited sphincterotomy up to one-third of the size of a full sphincterotomy. A balloon catheter is passed on guide wire across the papilla and centered at the sphincter. The balloon is then inflated and the sphincter gradually dilated to between 12 and 20 millimeters. One should observe for disappearance of wasting and the dilation is maintained for approximately 60 seconds. Precut sphincterotomy. The indications of precut sphincterotomy include failure of deep CBD cannulation and stone impaction at the papilla. It aims to achieve deep cannulation and gain biliary access by direct cutting onto the papilla and sphincter of oti. Various methods have been described, including freehand needle knife, needle knife fistulotomy, papillary roof incision, and transpancreatic precut sphincterotomy. The overall rate of success in gaining biliary access after precut sphincterotomy ranges from 35 to 96%. Randomized studies have shown similar rates of biliary access by the freehand needle knife technique as compared to persistent cannulation. However, the precut approach is associated with significantly more pancreatitis and perforation than in standard sphincterotomy. This video demonstrates precut sphincterotomy with the freehand needle knife technique. The incision began with the tip of the needle knife lodged at the papillary orifice. It was then extended upwards between 11 and 1 o'clock in a progressive manner to allow a step-by-step incision of the papillary sphincter. After the common bile duct channel was opened, bile was seen coming out from the orifice and cannulation of the CBD can then be performed. There is only limited data concerning the comparison of different methods of precut sphincterotomy. The results of a randomized study comparing precut fistulotomy against conventional needle knife precut showed similar rates of successful cannulation. There was, however, a significantly higher rate of pancreatitis in the conventional group. The fistulotomy group, on the other hand, required more use of the mechanical lithotriptor for stone retrieval. Extraction of Common Bile Duct Stones It is well known that 80-90% of common bile duct stones can simply be extracted with the use of endoscopic basket or balloon catheter. In general, stones smaller than 1 cm would require no extra accessories, and the chance of successful extraction is not affected by the number of stones in the common bile duct. However, when the CBD stone is bigger than 1.5 cm in diameter, lithotripsy via regular sphincterotomy can be difficult. In-situ fragmentation would be necessary unless the stone is of soft, muddy consistency. Measures available include the use of a basket mechanical lithotriptor, mother and baby colodocoscopy, electrohydraulic lithotripsy, intraductal laser lithotripsy, and extracorporeal shockwave lithotripsy. Most of these methods require expensive items which may not be universally available. A possible alternative is to insert one or two plastic stents for temporary biliary drainage, and to repeat ERCP 6-8 weeks later. Stone extraction by Dormier basket A variety of baskets with different sizes and configuration are available in the market, but so far there is no evidence to support the use of one over the other. The Dormier basket can remove the majority of CBD stones. It is more suitable to be used in dilated ducts, where the stones can be captured by a jiggling motion. Installing the instrument in non-dilated ducts may be tricky, as the stone will be difficult to engage when the basket is not fully opened. The instrument may also be useful in fragmenting soft stones, however the risk is that wires may become impacted on the stone, resulting in a trapped basket. Further, wires may fracture when trying to fragment large stones. The technique of Dormier basket extraction After an ample sphincterotomy, a closed Dormier basket is inserted into the lower common bile duct. Contrast is injected through the partially opened basket to allow better visualization of the basket in relation to the CBD stones. The basket can be fully opened when it lies next to or above the target stone. One should open it gently to avoid inadvertent upward stone displacement. Stones can be engaged by vigorously shaking the basket. In the presence of multiple calculi, it is advisable to catch the more distal one first in order to avoid entrapment of the basket within the common duct. In most cases, stone extraction is done simply by pulling the basket catheter along the axis of the common duct. Closure of the basket is unnecessary, as it may disengage the trapped stone. To align the force of the stone extraction with the CBD, the duodenoscope is pushed down with a right rotational movement. Downward angulation of the tip of the endoscope may add further pulling force when slight resistance is encountered. Multiple stones can be removed by repeating the above maneuver. This video demonstrates the technique of Dormier basket stone extraction. The closed basket was first introduced into the CBD and opened slightly to allow injection of contrast. It was then gently deployed to avoid upward displacement of the stones. The lower CBD stone was captured first and withdrawn to the papilla without closure of the basket. And the force of the stone extraction should be aligned with the axis of the CBD. Multiple stones can then be removed by repeating the above maneuver. Stone extraction using a balloon catheter. Balloon extraction catheters come in a number of different sizes and they can be either double or triple lumen to allow concurrent injection of contrast and guide wire insertion. The advantages of a balloon catheter is that they are useful in small caliber ducts when a basket cannot be fully deployed. It can also be used to test the adequacy of sphincterotomy prior to stone extraction. Further, the balloon can be used for performance of the occlusion cholangiogram. However, the balloon catheters are not suitable in massively dilated ducts, as the inflated balloon cannot effectively sweep the duct and small stones may slip past the balloon. Stone extraction using a balloon catheter. The deflated balloon catheter is first positioned above the target stone. It is then inflated with air to match the size of the CBD. The inflated balloon is thralled towards the sphincterotomy accompanied by a downward angulation of the endoscope. Stone fragments below the balloon will then be dragged out by the piston-like movement of the balloon. The balloon may need to be slightly deflated to allow passage through a narrow part of the common duct. Further traction of the balloon may be aided by pushing the duodenoscope down with a right rotational movement. In this video, multiple 1 cm stones were present in the common bile duct associated with a migrated stent in the common hepatic duct. The lower-most stones were first removed by the balloon catheter. The balloon was positioned above the target stone and inflated with air to match the size of the CBD. It was then trawled towards the sphincterotomy, dragging out the lower-most stones. Additional traction force was applied by downward angulation of the endoscope. The procedure was repeated to clear multiple bile duct stones that were present. The technique was also used to retrieve the migrated stent, where inflation of the balloon allowed engagement and delivery of the stent to the duodenum. Management of Giant CBD Stones Basket Mechanical Lithotripsy Basket Mechanical Lithotripsy has become the standard technique for management of giant CBD stones that are more than 2 cm in size. Success can be achieved in over 80% of the cases when balloon or basket extraction fails. The overall complication rate ranges from 3.6% to 5% and include trapped or broken basket, traction wire fracture, broken wire handle, and ductal perforation or injury. Technique of Basket Mechanical Lithotripsy The Basket Mechanical Lithotriptor consists of a dormant basket with an outer Teflon sheath. The basket is first used to capture the stone and it is then placed at the pre-papillary common bile duct. The Teflon is then withdrawn to facilitate advancement of the outer metal coil to allow crushing of the stone against it. The crushed stone is then pushed to the middle portion of the CBD to avoid impaction of stone fragments in the pre-papillary region. Caution needs to be taken during advancement of the metal coil as ductal injury is possible. The stone fragments can then be removed with basket and balloon extraction. In this video, the Mechanical Lithotriptor was used to capture the giant stone as in basket extraction. It was then placed at the middle part of the CBD and the Teflon withdrawn to allow crushing of the stone. The crushed stone was then placed at the middle portion of the CBD to avoid impaction. Caution should be made during advancement of the metal coil to avoid ductal injury. The fragments can then be removed by basket extraction. Mother and Baby Colodocoscopy and Intraductal Lithotripsy Mother and Baby Colodocoscopy is a technique that requires two operators controlling the mother duodenoscope and the baby colodocoscope. The baby colodocoscope is introduced through the channel of the mother duodenoscope and then into the bile duct. Intraductal lithotripsy can then be performed with either electrohydraulic or laser lithotripsy. In this video, demonstrating the technique of Mother and Baby Colodocoscopy, a nasobiliary drain was first inserted to allow continuous irrigation of saline to facilitate stone visualization. The baby colodocoscope was then introduced via the channel of the duodenoscope into the bile duct. Intraductal lithotripsy was performed with the electrohydraulic lithotriptor introduced through the channel of the colodocoscope. Continuous saline irrigation would be required to wash away stone fragments in order to maintain visibility. The small stone fragments were then removed with basket extraction. Electrohydraulic Lithotripsy Electrohydraulic lithotripsy involves the generation of high-voltage sparks which are discharged from the tip of the probe. This creates hydraulic pressure waves and causes stone fragmentation. The overall success rates ranges from 74 to 100%. However, only limited information is available regarding the frequency of complications. The complication rate of 18% was reported in one series and include cholangitis, jaundice, hemobilia, pancreatitis, and bile leak. Intraductal Laser Lithotripsy Laser lithotripsy causes stone fragmentation through a non-thermal photoacoustic effect. Currently, several types of laser are in use and include neodymium-doped yttrium aluminum garnet laser, the flash lamp pulse laser, and the frequency doubled double pulse laser. The reported success rates in small case series ranges from 80% to 97%. When compared to ESWL, laser lithotripsy has been shown to be more effective in terms of stone clearance rate and treatment duration, and is associated with only minor complications. Extracorporeal Shockwave Lithotripsy ESWL utilizes shockwaves to cause stone fragmentation and can be used for giant CBD stones refractory to mechanical lithotripsy. Localization of the stone is via sonographic control or contrast injection through a pre-inserted nasobiliary catheter. Stone clearance rates of 73% to 90% have been reported. Complications such as cholangitis or hematoma formation are rarely observed. Stenting and Interval ERC In patients with refractory CBD stones, plastic stents are frequently inserted as a temporary measure. The stent not only serves to provide temporary drainage, but also improves the solubility of bile and causes mechanical friction. Small case series have demonstrated a significant decrease in size of stones after insertion of plastic stents. Our practice is to leave the stents in situ for 4 to 6 weeks before repeating stone extraction. Interhepatic Ductal Stones Interhepatic ductal stones are common in the Far East. The condition is characterized by presence of multiple strictures and pigmented calculi in the interhepatic ducts. Interhepatic treatment is often difficult with surgery and percutaneous treatment being the main modes of treatment. Recurrence rates of 32.6% to 63.2% have been reported. During ERCP, the use of a wire-guided basket may help in selective cannulation of the desired duct. One should also be aware of the possibility of concomitant cholangiocarcinomas. Surgical Biliary Complications In this chapter, an overview on the causes and classifications of surgical biliary complications will be given. Further, the role of the endoscopist in management of these complications, which includes bile leaks, biliary strictures and other special conditions, will be discussed. Bile duct injuries are increasing in incidence, as laparoscopic cholecystectomy is now the gold standard in treatment of symptomatic cholelithiasis. The occurrence of these injuries can result in catastrophic outcomes. It can significantly impair the patient's physical and mental quality of life, reduce their long-term survival and are associated with high rates of litigation. Post-operative bile duct injuries are most common after laparoscopic cholecystectomy or biliary enteric anastomosis. These complications can present as bile leaks, biliary strictures or external fistulas. The management is often complicated and will require a multidisciplinary approach involving surgeons, endoscopists and interventional radiologists. Causes of Post-operative Biliary Complications Post-operative biliary complications can occur after gallbladder, bile duct or liver surgery. Both laparoscopic and open cholecystectomy can result in biliary complications due to cystic stump leak or injury to the biliary tract including the common bile duct, the peripheral hepatic ducts or the ducts of luschka. In common bile duct surgeries, the main complications include damage to the CBD or a major branch at the confluence, leakage from the choledocotomy site or from the anastomosis. In liver surgeries, injury to the CBD or a major bile duct branch at the confluence can also occur. Other complications involving the intrahepatic ducts may result from a ligated or clipped hepatic duct or from a leaking duct at the transected raw surface of the liver. Endoscopic Classification of Bile Duct Injury A number of different classification systems have been proposed for bile duct injuries. The one most relevant to the endoscopist was proposed by Bergman in 1996. In this classification system, type A injuries include cystic duct leaks or leakage from the aberrant or peripheral hepatic radicals. When the leakage is coming from major bile ducts, it will be classified as type B, irrespective of concomitant bile duct strictures. Type C injuries are defined as bile duct strictures in the absence of bile leakage. And type D injuries are when there is complete transection of the bile duct. So what role do endoscopists play in the management of bile duct injuries? Endoscopists play an important role in the management of these patients as a multidisciplinary team including surgeons, endoscopists, and interventional radiologists is recommended. ERCP serves two main purposes. First, it is to establish the diagnosis and classify the type of bile duct injury. A full cholangiogram should be performed with a patient at supine to depict the extent of the lesion. When ERCP is not possible, a percutaneous cholangiogram or magnetic resonance cholangiogram should be considered to allow complete mapping of the biliary tract. ERCP can also allow therapeutic intervention. The principle is to re-establish a pressure gradient that will favor the flow of bile into the duodenum and to provide drainage of the biliary system. Management of Bile Leaks Management of Bile Leaks In type A leaks, the options of endoscopic treatment include performance of an endoscopic sphincterotomy alone, or insertion of a plastic stent, or nasobiliary drainage with or without endoscopic sphincterotomy. When stents are being inserted, a size larger than 10 French is generally preferred. All of these methods are associated with more than 95% success rates and neither one was shown to be superior. At all instances, stones present at the CBD should be retrieved in order to remove any cause of ductal obstruction. In this video, the patient presented with a bile leak after a laparoscopic cholecystectomy four weeks ago. ERC and plastic stent insertion was performed at that time. Initial cholangiogram on repeat ERC showed a lower common bile duct stone and no evidence of contrast leakage. We proceeded to sphincterotomy and basket stone retrieval, however, during the course of the procedure, contrast leakage was noted and an ongoing leak from the cystic duct was suspected. A 10-french 13-centimeter plastic stent was then inserted to above the cystic duct to seal the site of leakage and to allow temporary drainage of bile. Each method nevertheless has their own limitations. Endoscopic sphincterotomy is associated with potential complications such as bleeding, perforation and pancreatitis. The insertion of plastic stents requires a second procedure for removal. The presence of a stent is associated with stent-related problems such as obstruction and migration. The insertion of a nasobiliary drain requires hospitalization. The drain is uncomfortable to the patient and has the risk of migration. However, a checked cholangiogram can be performed without a second procedure. Hence the choice of treatment will depend on the endoscopist's preference and the institution's expertise. Type B Leaks In type B leaks, the insertion of long stents to bypass the site of leakage is also preferred, and success rates of 71 to 79% have been reported. The presence of a stent across the narrowed site may also help to prevent stricture formation. Percutaneous drainage should be considered if drainage is inadequate after endoscopic stenting. Type D Leaks The patients with type D leaks will benefit most from early reconstructive surgery. Endoscopic canalation of the hepatic ducts can be attempted to allow temporary internal drainage. Yet most cases will require percutaneous drainage and surgical consultation. The patients suffering from these types of injury are associated with a poor long-term quality of life and they are best managed by a multidisciplinary team. Bioleaks and Fistula Post-Liver Transplant Bioleaks and fistulas are the most common biliary complications after liver transplantation. Leaks can be from the T-tube exit site, anastomotic site, or the cut surface of the liver. The management strategy is similar to bioleaks seen after cholecystectomy, and endoscopic therapy is the preferred initial approach. Insertion of a plastic stent or nasobiliary drain across the leak site is associated with high rates of healing within a week. However, there is risk of subsequent development of stricture at the leakage site. The failure to heal is an indication for early surgery to prevent ongoing sepsis in an immunocompromised host. Post-Traumatic Bioleaks The management of patients suffering from multiple trauma involves the concept of damage control surgery. The aim is to avoid complex reconstructive surgery in a hemodynamically unstable patient. The presence of a traumatic bioleak is often difficult to diagnose in a patient with multiple trauma and a high index of suspicion is required. The use of ERCP offers both diagnostic and therapeutic value. Once a leak is confirmed, stent placement to bypass the site will allow resolution of the bioleak in up to 90% of patients, and complex reconstructive surgery may be avoided. Post-Cholcystectomy Strictures These strictures are traditionally managed by surgical means. However, surgery is associated with significant risks, with morbidity rates of 18 to 51% and mortality rates of 4 to 13% being reported. The recurrence rate is also high and is up to 30%. On the other hand, endoscopic therapy has a high initial success rate of up to 90% and the procedure is associated with a low morbidity and mortality rate. The recurrence rate is also comparable to surgery and it is between 9 and 20%. Hence, endoscopic therapy is gaining acceptance as the treatment of choice in patients with post-cholcystectomy strictures. At present, however, there is a lack of randomized studies comparing surgery versus endoscopic therapy, but some retrospective studies have shown similar rates of long-term success for both approaches. Principles of Endoscopic Treatment The principle of endoscopic treatment involves placement of the maximal number of plastic stents across the stricture site. This allows remodeling of the stricture around the stents and maintains bile duct patency after stent removal. One should aim for placement of the maximal number of stents and most series place at least 2 to 3, 10 French stents. Endoscopic sphincterotomy is not mandatory but will facilitate multiple stent placement. The stricture should be dilated if difficulty is anticipated in crossing the stricture. The optimal duration of stenting is uncertain, but most series place stents for 12 months and aim for stent exchange every 3 months. This video illustrates a patient who suffered from a cystic duct stump leak after cholcystectomy. He was treated with ERC and plastic stent insertion. However, he developed a CBD stricture at the level of the cystic duct stump and was scheduled for multiple stenting. Endoscopic sphincterotomy was first performed to facilitate subsequent insertion of multiple stents. The aim is to insert the maximal number of stents and at least 2 to 3, 10 French stents should be inserted. Stents should be inserted to above the stricture site and the first stent is the easiest to deploy. On insertion of the second stent, the use of a rotational torque movement in conjunction with a fully elevated bridge may help negotiate the stent through the tight stricture. One should be cautious that insertion of the additional stents may result in proximal migration of the stents already deployed. A biliary dilator was used in this patient to dilate up the stricture site and to facilitate insertion of the third stent. Stents are kept in Saichi for three months and scheduled for exchange. The Technique of Multiple Stenting A full cholangiogram is first performed to confirm the location and extent of the stricture. A guide wire is used to traverse the stricture and to allow passage of the sphincterotome or the catheter. Performance of a complete sphincterotomy will make subsequent insertion of multiple stents easier. Tight strictures can be dilated with mechanical or pneumatic dilation to allow passage of additional 10 French stents. The aim is to insert the maximal number of stents permitted by the stricture and at least 2 to 3 10 French stents should be inserted. Stents should be scheduled to be exchanged every three months and increasing number of stents can be inserted on subsequent sessions. The procedure is repeated until complete disappearance of stricture. In the current video, the patient suffered from a lower common bile duct stricture due to previous motor vehicle accident. The metallic stent that is present was inserted for a portal vein stricture secondary to open repair. A simple cholangiogram was first performed to delineate the extent of the CVD stricture which was confined to the lower common bile duct. A full sphincterotomy was performed in the previous ERC session to facilitate insertion of multiple stents. The stents were sequentially inserted to above the stricture. As increasing number of stents were inserted, there will be a tendency for the deployed stents to migrate upwards. This can be overcome by slowly inserting the stents with a sideways torque movement which changes the axis of the force being applied. Dilation of the stricture with a biliary or pneumatic dilator can be performed for tight strictures, but it was not required in this patient. One should aim for insertion of at least two to three ten French stents. A total of four plastic stents were inserted for this patient and they were repositioned by forceps after completion of the procedure. The Role of Metallic Stents Uncovered metal stents are generally not recommended as they are difficult to retrieve, associated with a risk of migration, and have a limited patency period. The use of covered metal stents, on the contrary, may be a viable option due to the ease of stent insertion and retrieval. Initial success have been reported in high-risk patients in a recent small case series. When Does Endoscopic Therapy Fail? Successful dilation of the bile duct stricture can be achieved in 74 to 90% of the patients. Recurrence rates of up to 20% two years after endoscopic therapy have been reported. The predictors of successful outcome after treatment include increasing number of stents being inserted and injuries located distal to the biliary bifurcation. Surgery should be considered in patients with stent dependency after more than one year of stenting, stricture recurrence after removal of the plastic stents, and in those with complete transection of the CBD. Endoscopic Strictures Post-Liver Transplant These strictures can be classified into anastomotic and non-astomotic strictures. Anastomotic strictures associated with deceased donor transplants are located at common hepatic duct, while those associated with living-related transplants are located at the second or third order bile duct branches. The presence of anastomotic strictures are related to surgical technique or graft ischemia and often respond well to endoscopic treatment. Non-anastomotic strictures are strictures located proximal to the anastomotic site. They are usually multiple and are due to global ischemia of the graft. These strictures are associated with poor prognosis and the aim of the endoscopic therapy is to buy time from retransplantation. In patients with anastomotic strictures, the optimal management is still uncertain. However, there is accumulating evidence in support of aggressive endoscopic therapy. The technique is similar to the management of post-cholcystectomy strictures and involves serial endoscopic balloon dilation with maximal stent placement. This strategy is associated with up to 90% success rate and the potential advantages include shortened duration of endoscopic treatment and a reduction in the number of procedures in the immunocompromised patient. In this video, MRCP demonstrates a patient suffering from an anastomotic biliary stricture after orthotopic liver transplant. A full cholangiogram was first performed to delineate the level of the stricture. It was then dilated with the balloon catheter aiming for maximal stent placement. The sphincter was similarly dilated with the balloon catheter in order to facilitate insertion of multiple stents. One should aim for aggressive endoscopic therapy with maximal stent placement, which is associated with high rates of success. The plastic stents were inserted serially to above the stricture in a manner similar to the methods previously described. A total of three plastic stents were inserted in this patient. Management of Special Conditions Biliary Cast Syndrome Biliary Cast Syndrome is defined as the presence of retained lithogenic material morphologically confined to the bile duct dimensions. The presence of these lithogenic material can result in bile duct obstruction or cholangitis. The syndrome can occur in up to 18% of liver transplant recipients and the exact cause is uncertain. Postulated etiologies include ischemia, strictures and cholangitis. The best management remains controversial. Both endoscopic and percutaneous approaches have been described, with success rates ranging between 24 to 70%. In the endoscopic approach, bile duct access is gained by sphincterotomy or sphincteroplasty. The use of sphincteroplasty has been suggested to preserve the function of the sphincter of OTI. This may reduce duodenal reflux, leading to reduced risk of ascending infection. The methods of cast retrieval are similar to those used in removal of ductal stones. However, extensive cast formation in the biliary tree may mandate repeated endoscopic sessions, and other options such as percutaneous or surgical removal should be considered. ERC in Post-Biliary Enteric Anastomosis The main difficulty of ERC after surgical biliary enteric anastomosis is the method of reaching the papilla via the long afferent limb. A variety of methods have been described, and these include the use of conventional side-viewing endoscope, pediatric colonoscope, single-balloon and double-balloon enteroscope. Percutaneous transhepatic access can be performed as the final option. Once access is gained, therapy can be performed accordingly. Benign Biliary Strictures The aim of this chapter is to cover the background, etiology, and management of benign biliary strictures, with particular emphasis on chronic pancreatitis and Merisi's syndrome. Background Benign biliary strictures may result from acute or chronic inflammation of the bile duct. These strictures may be single or multiple. If left untreated, they may result in secondary biliary cirrhosis and portal hypertension. Benign biliary strictures can result from a wide range of conditions. It is most commonly caused by surgery or chronic pancreatitis. Other causes include primary sclerosing cholangitis, post-traumatic strictures, stone diseases, and radiotherapy. Stricts marked with an asterisk will be covered in other chapters. Chronic Pancreatitis Chronic pancreatitis accounts for 10% of all benign biliary strictures. The aim of the endoscopic therapy include treating the complications arising from pancreatitis such as pseudocysts or biliary obstruction, and achieving pancreatic ductal drainage in patients with chronic pain or recurrent pancreatitis. For the purpose of this review, only endoscopic therapy concerning biliary strictures resulting from chronic pancreatitis will be discussed. Biliary obstruction in chronic pancreatitis occurs in 2.7 to 45.6% of patients with chronic pancreatitis. It occurs as a result of chronic fibrosis in the head of the pancreas or from extrinsic compression by a pseudocyst. The definition of a CBD stricture is when there is dissonaring of CBD with proximal dilation of more than or equal to 12 mm, or when there is delayed contrast drainage into the duodenum. Most CBD strictures in chronic pancreatitis are asymptomatic and do not require treatment. Endoscopic therapy for treatment of chronic pancreatitis-related strictures is associated with a high rate of initial success and resolution of symptoms, and this should be the initial choice of therapy. The indications of treatment include recurrent cholangitic attacks, obstructive jaundice and increased ALP levels to more than or equal to 2 times normal for more than 4 weeks. The options of endoscopic therapy include plastic or metallic stenting, and the presence of malignant pancreatic stricture should be excluded. Single versus multiple plastic stenting. Insertion of a single plastic stent is the simplest method of obtaining biliary drainage in patients with chronic pancreatitis. After CBD access is gained, the stricture is dilated with a bougie or balloon. A single 10 French stent is then inserted and exchanged every 3 to 4 months. This method is associated with a high success rate and an immediate improvement in liver function. However, only 10 to 28% of patients will have sustained relief. The aim of multiple stenting is to generate a persistent force to maintain dilation at the largest diameter over the biliary stricture. A maximal number of plastic stents ranging from 7.5 to 10 French in size are inserted and exchanged every 3 to 6 months. Two small non-randomized studies have shown that multiple stenting is associated with higher rates of sustained resolution as compared to single plastic stenting. And an increase in the mean common bile duct diameter from 1 mm to 3 mm was also observed. This cholangiogram demonstrates a distal CBD stricture secondary to chronic pancreatitis. After CBD access is gained, the stricture is dilated with a hurricane balloon from 8 to 10 mm for 60 seconds. A second guide wire is then inserted to facilitate sequential insertion of two plastic stents. The technique of multiple stenting is similar to the technique as described previously. The stents will be exchanged every 3 months and one should aim to insert increasing number of stents in subsequent sessions. This technique of multiple stenting has been shown to be associated with higher rates of sustained resolution and an increase in mean bile duct diameter. The use of uncovered metallic stents can allow resolution of biliary obstruction. However, it poses certain problems including limited long-term patency, difficulty in retrieval, the potential to complicate subsequent surgical procedures and the risk of developing cholangiocarcinoma. Recently, however, the use of covered metallic stent has been reported and it appears to be promising modality. Up to 90% of patients had resolution of stricture in one year The stent could also be removed without difficulty with snare or rat tooth forceps. However, 14% of patients experienced stent migration and the role of metallic stenting will require further evaluation. Failure of endoscopic treatment The presence of calcifications in the pancreatic head is the only risk factor identified for failure of endoscopic treatment and this is associated with a 17-fold increase in risk. When endoscopic therapy fails, treatment options include repeated endoscopic stenting or surgical bypass. The decision on which approach to embark on is based on balancing the risk of surgery versus repeated endoscopic treatment for the patient. Merici Syndrome Merici Syndrome Merici Syndrome results from obstructive jaundice caused by a stone impacted at the neck of the gallbladder or cystic duct leading to narrowing of the common hepatic duct. It may be associated with the cholecystocolodocal fistula and affects 0.1 to 0.7% of patients with gallstones. The condition is also associated with increased risk of cholangiocarcinomas. Merici Syndrome can be classified into four types. In type 1, biliary obstruction occurs as a result of extrinsic compression of the common bile duct with absence of a fistula. In type 2, a fistula is present and involves less than one-third of the circumference of the bile duct. In type 3, a fistula is present and is up to two-thirds of the circumference of the bile duct. And in type 4, there is complete destruction of the bile duct wall. Diagnosis The role of the endoscopist in managing patients with suspected Merici Syndrome includes establishing the diagnosis, delineating the cause, level, and extent of obstruction, and providing temporary drainage to the biliary system. Diagnosing Merici Syndrome requires a high index of suspicion. A correct diagnosis is only made in 8 to 62.5% of the patients, and in unrecognized patients, the risk of bile duct injury on subsequent surgery is high. The diagnosis should be suspected in the presence of a large gallstone associated with dilation of the common bile duct, and the presence of a malignant biliary stricture should be excluded. In the management of Merici Syndrome, a cholangiogram is needed to delineate the cause, level, and extent of obstruction, and this can be achieved by either MRCP or ERCP. MRCP is a non-invasive test and carries a high sensitivity and specificity in detecting gallstones, bile duct stenosis, and malignancy. The diagnosis of Merici Syndrome should be suspected when there is narrowing or curvilinear compression of the common hepatic duct associated with proximal ductal dilation and inflammation of the gallbladder. ERCP, on the other hand, has sensitivity of up to 100% and is the most sensitive test. Further, it allows placement of a plastic stent for temporary drainage. The patients can then be stabilized before surgical exploration. Endoscopic stone retrieval may also be attempted in poor-risk patients. In this chapter, an overview on the background, diagnosis, and endoscopic therapy of primary sclerosing cholangitis will be discussed. Primary sclerosing cholangitis is a chronic cholestatic syndrome of unknown etiology. It is characterized by diffuse fibrosing inflammation of the intra- and extrahepatic biliary ductal systems. The disease progressively advances and results in biliary cirrhosis, portal hypertension, and liver failure. The condition is currently one of the most common indications for liver transplantation in adults. The disease most commonly affects young and middle-aged men. It is associated with inflammatory bowel diseases and carries a risk of developing cholangiocarcinomas. The typical symptoms of primary sclerosing cholangitis include fatigue, pruritus, and jaundice. Secondary causes of biliary cirrhosis will need to be excluded, and the p-anchor is positive in up to 80% of the patients. Histologically, the condition is classified into four stages. Stage 1 is characterized by presence of cholangitis or portal hepatitis. Stage 2 involves periportal hepatitis or fibrosis. Stage 3 is characterized by necrosis, septal fibrosis, or fibrosis extending beyond the limiting plate. And stage 4 disease is characterized by the presence of biliary cirrhosis. ERCP is the gold standard in diagnosis of PSC. The characteristic cholangiographic features include a beads-on-string appearance, which is defined by diffusely distributed multifocal annular strictures with intervening normal or slightly ectatic ducts, short band-like strictures, diverticulum-like outpouchings, and the presence of dominant strictures, which are high-grade, localized area of narrowing at the confluence or the common duct. The involvement of both the cystic and pancreatic duct is also possible. MRCP, on the other hand, is a non-invasive test that offers comparable sensitivity to ERCP, ranging from 85 to 90%. Hence, MRCP can be used as a screening test, followed by ERCP, when diagnostic doubt arises, and this has been shown to be the most cost-effective approach. The advantages of MRCP include the capacity to visualize ducts proximal to a tight stricture, avoidance of the risks of radiation, pancreatitis, and other potential complications of ERCP. It also provides additional information on liver cirrhosis, ascites, and other focal liver lesions. However, MRCP is less sensitive in diagnosing extrahepatic ductal strictures and early PSC, and the modality has a poor yield in detecting cholangiocarcinomas. The progressive inflammation of primary sclerosing cholangitis can result in obliteration of the bowel ducts. The management can be through percutaneous, endoscopic, or surgical approaches. Currently, the endoscopic approach is preferred, as it is associated with clinical and biochemical improvements in patients with dominant strictures. It is also associated with a low rate of complications and improvements in the overall survival. This is important, as these patients will frequently need a repeated procedure to maintain biliary patency. Dominant strictures are partial or total stenosis of the common hepatic duct or the confluence. This occurs in 7 to 20% of patients with PSC and may result in sudden deterioration of liver function or acute cholangitis. Using multivariate analysis, the presence of dominant strictures is an independent predictor for successful endoscopic therapy. The treatment options include stenting, balloon dilation, or nasobiliary catheter drainage, and the best method is still controversial. Both endoscopic balloon dilation and stenting are effective therapies for treatment of dominant strictures. However, there is a lack of randomized controlled trials comparing these techniques. In endoscopic stenting, long-term stenting is associated with the risk of occlusion and cholangitis. Up to 50% of patients require non-nelective ERCP with stent exchange or removal. On the contrary, short-term stenting appears to be associated with sustained improvements in liver function in up to 80% of the patients after one year. Endoscopic balloon dilation has been shown to be associated with short-term and long-term benefits. The technique requires multiple sessions to achieve sustained dilation, and the addition of a stent has not shown to confer further benefits. Rather, the use of stents have led to increased incidence of stent-related complications and increased number of interventions. The technique of endoscopic balloon dilation in patients with primary sclerosing cholangitis. After biliary access is gained, a full cholangiogram is performed. Any stricture is dilated with polyethylene balloons ranging from 4 to 8 mm in diameter and 3 to 4 cm in length. A graduated dilator can be used for tight strictures not emitting the balloon catheter. The presence of stones or debris should be removed, and breast cytology should be obtained in strictures suspicious of cholangiocarcinomas. The procedure can be repeated when the patient becomes symptomatic. This cholangiogram shows a typical beads-on-string appearance and the presence of a dominant stricture in a patient with primary sclerosing cholangitis. An 8 mm hurricane balloon is being inserted to the site of the stricture and the balloon is inflated. During inflation, there may be a tendency for the balloon to migrate away from the site of narrowing and hence careful positioning of the balloon is important. The procedure can be repeated when the patient becomes symptomatic. There is no clear guideline on when endoscopic therapy should stop. Only one study compared surgical endoscopic and percutaneous therapy in management of dominant strictures. The study has shown that surgery is associated with significantly longer transplant-free survival and overall survival as none of the patients developed cholangiocarcinoma. Procedure-related complications were highest in the percutaneous group, followed by surgery and endoscopic therapy. Hence, endoscopic management should be used as the initial approach and surgery should be considered when endoscopic therapy fails and the patient continues to experience significant symptoms. In this chapter, we will be discussing the pathogenesis, classifications, diagnosis, and treatment of biliary and pancreatic sphincter-of-audi dysfunction. Functional gallbladder and sphincter-of-audi disorders are a group of disorders characterized by similar clinical manifestations. The latest ROM3 diagnostic criteria have subclassified these disorders into functional gallbladder disorder, functional biliary sphincter-of-audi disorder, and functional pancreatic sphincter-of-audi disorder. The following table shows the diagnostic criteria of functional gallbladder and sphincter-of-audi disorders. The aim of this stringent criteria is to rule out other disorders that may present with similar pain syndromes. These include reflux disease, functional dyspepsia, and irritable bowel syndrome. Further, it is also aimed to reduce unnecessary invasive procedures and interventions in patients presenting with upper abdominal pain. The pathogenesis of biliary sphincter-of-audi disorder. Sphincter-of-audi dysfunction occurs as a result of motility abnormalities of the sphincter-of-audi contraction. This causes a non-calculus obstruction to the flow of bile or pancreatic juice at the level of sphincter-of-audi. This syndrome is characterized by pain, abnormal liver function test, pancreatitis, or dilated ducts. The condition has a predominance in female and cholecystectomized patients. Sphincter-of-audi consists of small muscle fibers at the end of bile duct, pancreatic duct, and the confluence of the two, the normal function of which is to maintain a sterile intraductal lumen and to regulate the flow of bile and pancreatic juice. The following table shows the classification of sphincter-of-audi dysfunction. The main revision from ROAM-II criteria is that drainage times are not required for diagnostic purposes. One should also avoid premature ERCP so as to lessen the risk of procedure-associated morbidities. In type 1 SOD, these patients are characterized by recurring biliary-type pain associated with abnormal liver function tests. They will also suffer from sonographic or manometric abnormalities. This is the group of patients that are most likely to suffer from This is the group of patients that are most likely to have symptomatic improvement after endoscopic sphincterotomy. On the contrary, in type 2 and 3 SODs, the abnormalities in liver function tests, sonography, and manometry are less consistent, and these patients are associated with a variable response to sphincterotomy. Sphincter-of-audi manometry is the gold standard for diagnosis of sphincter-of-audi dysfunction. A basal sphincter pressure of greater than 40 millimeters mercury is diagnostic of the condition. Other manometric abnormalities include increased amplitude of phasic waves, paradoxic response to cholecystokinin analogs, increased frequency of phasic waves, and increased number of retrograde waves. The technique of sphincter-of-audi manometry requires advanced ERCP skills. One should avoid drugs that relax or stimulate the sphincter 8 to 12 hours prior to the procedure. These include nitrates, calcium channel blockers, cholinergics or anticholinergics, glucagons, and narcotics. Manometry should be performed with a 1.7 millimeters triple-lumen side-hold manometric catheter. Aspiration of fluid through one port has been shown to significantly decrease the risk of pancreatitis. This will not affect the SOM pressures and should be employed during the procedure. After deep cannulation of the bowel and pancreatic ducts, a full cholangiogram or pancreatogram should be performed to rule out structural abnormalities. One should then slowly withdraw the catheter across the sphincter at 1 to 2 millimeters intervals by standard stationary pull-through technique. This video demonstrates the technique of sphincter-of-audi manometry. The manometry catheter is inserted on guide wire across the sphincter after deep cannulation. The catheter is then slowly withdrawn at 1 to 2 millimeter intervals. During manometry, the catheter is perfused with distilled water at 0.25 milliliters per channel using a 1.7 milliliter tube. The catheter is perfused with distilled water at 0.25 milliliters per channel using a capillary infusion system. Care should be taken to ensure that the catheter is not impacted against the ductal wall. Any abnormalities on manometry should be observed for at least 30 seconds and be present in two or more pull-throughs. The basal sphincter pressure is taken as the average basal sphincter pressure. The amplitude of phasic wave contraction is measured from the beginning of the slope to the peak of the contraction wave. A total of four representative waves should be taken and the mean pressure calculated. A basal sphincter pressure of more than 40 millimeters mercury is indicative of sphincter-of-audi dysfunction. The most common complication of sphincter-of-audi manometry is acute pancreatitis, where the sphincter-of-audi dysfunction has been shown in studies to be a significant risk factor for post-ERCP pancreatitis. Methods to decrease rate of pancreatitis include the use of continuous aspiration during manometry and insertion of a pancreatic stent. During manometry, one should avoid water infusion in all three ports and use the middle port for continuous aspiration. This has been shown to decrease the rate of pancreatitis from 23.5% to 3%, and it did not alter pressure measurements. Insertion of a pancreatic stent has also been shown to decrease the rate of pancreatitis from 26% to 2.4%, and a 3 or 5 French stent can be inserted to improve the drainage from the pancreatic duct. In treatment of SOD, the aim is to relieve the abdominal pain and improve quality of life. Available options include pharmacological therapy, endoscopic sphincterotomy, and surgical sphincteroplasty. The current recommendation from the Rome 3 criteria is listed in this slide. Patients with type 1 SOD should undergo endoscopic sphincterotomy without manometry. In type 2 patients, ERCP with manometry should be performed. In the presence of raised sphincter pressures, endoscopic sphincterotomy should be performed. In type 3 patients, they should undergo a trial of nidvetepin before invasive procedures. Non-responsive patients should consider sphincter of oddy manometry, and the presence of sphincter of oddy dysfunction is an indication for sphincterotomy. The use of botulinum injection for selection of patients with normal SOM can also be considered. Endoscopic sphincterotomy Endoscopic sphincterotomy is the current standard of treatment in SOD, the outcomes of which have been shown to be comparable to surgical sphincteroplasty. Endoscopic sphincterotomy is associated with symptomatic improvement in type 1 patients and some type 2 patients with elevated sphincter pressure. However, the role in type 3 patients is less well-defined. This video demonstrates endoscopic sphincterotomy in a patient with biliary sphincter of oddy dysfunction. A pancreatic stent is inserted to decrease the risk of post-ERCP pancreatitis after manometry. The CBD is then deeply cannulated and sphincterotomy performed in the usual manner. The incision should be towards the 11 to 12 o'clock, and the upper extent of the cut should be up to the transverse mucosal fold. Botulinum toxin injection to the sphincter of oddy. Injection of botulinum toxin can be used as a method of selecting patients for endoscopic sphincterotomy or for long-term treatment. A small randomized trial has shown that pain improvement after injection correlates well with response to endoscopic sphincterotomy in type 3 patients. Further, it may also be used for endoscopic sphincterotomy in type 2 patients. This video demonstrates the technique of botulinum toxin injection into the sphincter of oddy. After prior pancreatic stent insertion, botulinum toxin is being injected into the four quadrants of the sphincter of oddy. One hundred mouse units of botulinum toxin was diluted in one milliliter of isotonic saline, and the injection was performed in the four quadrants of the sphincter of oddy. One hundred mouse units of botulinum toxin was diluted in one milliliter of isotonic saline, and the injection was performed with a sclerotherapy needle. The effects of the toxin generally wears off after 6 to 12 months, and the technique is useful in selecting potential responders to endoscopic sphincterotomy. There is some evidence showing that pancreatic sphincter of oddy dysfunction is associated with recurrent episodes of pancreatitis. Manometric abnormalities can be demonstrated in 15 to 72% of patients, and pancreatic sphincterotomy is associated with termination of pancreatitis in some patients. The ROM3 criteria for pancreatic sphincter of oddy disorder includes all of the criteria for functional gallbladder and sphincter of oddy disorder and the presence of elevated amylase or lipase during the attack of pain. Pancreatic sphincter of oddy manometry is a direct and objective method of identifying patients with pancreatic SOD. Abnormal pancreatic sphincter of oddy may be present with or without biliary SOD. The technique of pancreatic SOM is similar to the technique as described previously. However, canalation of the pancreatic duct is required. Pancreatic sphincter of oddy dysfunction is present if the basal pressure is more than 40 mmHg and evaluation should be performed at the same time as biliary sphincter of oddy manometry. Further, aspiration during manometry and pancreatic stenting is recommended to prevent post-manometry pancreatitis. The best treatment for patients with manometric evidence of pancreatic SOD is complete division of the sphincter of oddy. This can be performed by either surgical or endoscopic means, providing similar short-term results. Currently, endoscopic pancreatic sphincter of oddy is the preferred method. Whether geopancreatic biliary sphincter of oddy will be beneficial to these patients is still uncertain. The technique of pancreatic sphincter of oddy Two main methods have been described in the literature and these include the pull-type and needle-knife sphincter of oddy. In both techniques, prior pancreatic canalation with guide wire is recommended. There appears to be some evidence showing that needle-knife sphincter of oddy is associated with lower rates of pancreatitis. The technique of pull-type pancreatic sphincter of oddy is similar to the technique of pull-type biliary sphincter of oddy. Cutting of the sphincter should be performed slowly with the pure-cut current. One should cut with the very distal part of the wire and aim towards the 1 to 2 o'clock position to the floor of the papillary orifice. A complete sphincterotomy measuring 5 to 10 mm should be performed. Post-procedural stenting is recommended to prevent pancreatitis. Whether biliary sphincterotomy should be performed prior to pancreatic sphincterotomy is uncertain. The potential advantages include easier identification of the pancreatic biliary septum and decreased risk of injury to the distal bile duct. This video demonstrates the technique of biliary and pancreatic sphincterotomy with a pull-type sphincterotome. A pancreatic stent is first inserted to reduce the risk of post-ERCP pancreatitis. The CBD is then deeply cannulated and biliary sphincterotomy is performed in the usual manner. This is followed by deep canalation of the pancreatic duct. Cutting of the pancreatic sphincter should be done with a pure cut current, with the very distal part of the cutting wire. The cut should be directed towards the 1 and 2 o'clock position, and the sphincter tome is slightly bowed to avoid excessive tension. The cut is continued in a stepwise manner towards the roof of the papilla, and one should aim for complete sphincterotomy, measuring 5 to 10 millimeters in size. The technique of needle-nose sphincterotomy Needle-nose sphincterotomy is commonly performed after placement of a pancreatic stand, which acts as a guide towards the plane of the duct. The cut should begin at the most proximal portion of the pancreatic sphincter, and aiming for unroofing of the major papilla. The length of the cut is generally 5 to 10 millimeters in size. Prior biliary sphincterotomy and exposure of the pancreatic biliary septum allows better tissue access and more effective septotomy.

endoscopic retrograde cholangiography

benign biliary diseases

common bile duct stones

surgical biliary complications

benign biliary strictures

sphincter of Oddi dysfunction

endoscopic sphincterotomy

balloon catheter

laser lithotripsy

pancreatic SOD management