Treatment of Distal Malignant Biliary Obstruction by Uncovered, Partially Covered, or Fully Covered Metal Stents

The goal of this randomized controlled trial is to compare uncovered, partially covered, and fully covered self-expandable metal stents (SEMS) in the palliative treatment of distal malignant biliary obstruction in a Swedish multicenter study. The main questions it aims to answer is: Is the stent patency rate different depending of stent type? Is the stent patency time different depending of stent type? Is the patient survival different between the groups? Which complications are seen, and do they differ between the groups? Are there different mechanisms behind the stent failure depending on stent type? Patients will at ERCP, with a guidewire passed through the stenosis in the bile duct, be allocated to either uncovered, partially covered, and fully covered (SEMS). Totally, 450 patients will be recruited, 150 in each study arm, according to the power analysis. Patients will be followed in a monthly surveillance by a study nurse up to 12 months after stent insertion. Endpoints are: alive after 12 months with a patent stent, death with a patent stent, stent dysfunction with a subsequent intervention i.e. repeated ERCP or PTC = "objective stent failure", stent dysfunction, jaundice or cholangitis, but not intervention has been undertaken due to a poor condition of the patient, "clinical stent failure", the patient has undergone curative surgery or a bilio-enteric by-pass (a gastro-enteroanastomosis or a duodenal stent is not a reason for exclusion), the patient refuses further follow-up.