Endoscopic treatment for distal malignant biliary obstruction.

Distal malignant biliary obstruction (MBO) leads to obstructive jaundice as a result of when the bile excretion from the liver is disturbed and induces hepatic failure and sepsis, which when complicated with cholangitis, it becomes necessary to perform drainage for the MBO. For biliary drainage, we can perform a surgical bypass operation, percutaneous transhepatic biliary drainage (PTBD), endoscopic biliary drainage (EBD) via duodenal papilla, or endoscopic ultrasound (EUS)-guided biliary drainage (EUS-BD), which is a transgastrointestinal biliary drainage. Although currently we usually perform EBD for distal MBO to begin with, the choice is different for biliary drainage in patients in whom EBD has failed in a preoperative case or an unresectable case. In other words, we choose PTBD for preoperative cases, and PTBD or EUS-BD according to the ability of the institution for their procedures when EBD has failed. It is desirable not to choose a plastic stent (PS) but a self-expandable metallic stent (SEMS), in particular for the unresectable cases of pancreatic cancer it is desirable not to choose an uncovered SEMS but a covered SEMS in EBD. Nevertheless, further examinations are expected to decide which, a covered or uncovered SEMS, we should choose in unresectable biliary tract cancer (BTC) and whether we should select PS, SEMS or ENBD in preoperative cases.