This is a retrospective study to evaluate the outcomes of endoscopic biliary drainage according to the timing of distal malignant biliary obstruction (MBO) in relation to gastric outlet obstruction (GOO) and the location of GOO.

This is a multinational multicenter retrospective cohort study to evaluate the outcomes of endoscopic biliary drainage in patients with a duodenal SEMS. Endoscopic ultrasound-guided biliary drainage (EUS-BD), including choledochoduodenostomy, hepaticogastrostomy, antegrade biliary stenting or a combination, and endoscopic retrograde cholangiopancreatography (ERCP) with stenting are to be compared. Specifically, the outcomes are to be evaluated according to the timing of distal MBO in relation to GOO and the location of GOO.

Inclusion Criteria:

• Patients who underwent endoscopic placement of a duodenal SEMS for nonresectable malignant GOO.
• Patients who underwent endoscopic biliary drainage for nonresectable MBO.
• MBO was located ≥ 2 cm from the bifurcation.
• Patients who could be followed up more than three months after completion of both biliary drainage and duodenal SEMS placement.
• Age ≥20 years.
• Irrespective of sex and a primary disease.

Exclusion Criteria:

• Patients who underwent surgical bypass for GOO.
• Patients who underwent percutaneous and surgical biliary drainage prior to the placement of duodenal SEMS.
• Patients with altered gastrointestinal anatomy (Billroth-II reconstruction, Roux-en-Y reconstruction, etc.).
• Patients who would not give a consent to the report of their own data.
• Patients considered ineligible for inclusion in the study by an investigator for other reasons.

Patients who underwent the initial duodenal SEMS between Jan/1/2010 and Jun/30/2014 are included.