The role of anti-reflux biliary stent in patients with unresectable non-hilar malignant biliary obstruction: a prospective randomized study

INTERVENTION: Control group:Ordinary metal stent was implanted;anti‐reflux biliary stent group:Anti‐reflux biliary stent was implanted ; CONDITION: unresectable non‐hilar malignant biliary obstruction PRIMARY OUTCOME: Stent patency;Survival of patient; SECONDARY OUTCOME: Serum bilirubin;Unexplained fever;Technical Success of stent placement; INCLUSION CRITERIA: 1. Unresectable non‐hilar malignant biliary obstruction was confirmed by pathology or US, CT and/or MRI, or not a candidate for curative surgical resection due to operative risk or patient wishes; 2. Patients is 20 to 80 years of age; 3. Total Bilirubin>34.2umol/L (normal<17.1umol/L); 4. Information given and informed consent obtained.