| The most common causes of malignant biliary obstruction are pancreatic adenocarcinoma and cholangiocarcinoma. Other less common causes include metastatic cancer of the pancreas or liver, ampullary tumors with bile duct extension, gallbladder cancer, and perihilar metastatic lymphadenopathies. Unfortunately, malignant biliary obstruction are often diagnosed at an advanced stage and not amenable to surgery. The primary goal of endoscopic treatment in these patients is generally palliative, providing biliary decompression and directed tumor therapy. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) play important roles in managing malignant biliary stenoses. For endoscopic biliary drainage, there are different strategies depending on locations of stenosis (distal or perihilar region) and resectability of the tumor. Self-expandable metal stents (SEMS) have been shown to be superior to plastic stents with regard to patient outcomes and cost-effectiveness. However, plastic stents remain a reasonable alternative for patients with a life expectancy of less than three months. For perihilar cholangiocarcinoma, drainage of at least 50% of the liver is recommended. Bilateral placement of SEMS seems to be more effective than unilateral drainage in terms of stent patency and lower re-intervention rates. For resectable periampullary cancer or cancer of the pancreatic head, preoperative biliary drainage should be only considered in patients with symptomatic obstructive jaundice or infection. In patients with obstructive jaundice and failed ERCP due to surgically altered anatomy or duodenal stenosis, endoscopic ultrasound-guided biliary drainage (EUS-BD) has emerged as an alternative for biliary drainage. The choice of transduodenal and transhepatic approaches for EUS-BD depends on the location of stenosis and gastrointestinal anatomy. The use of covered SEMS is preferred to plastic stents for EUS-BD to reduce the risk of bile leak. |
