Endoscopic retrograde biliary drainage (ERBD) is now widely accepted as the standard intervention for the relief of obstructive jaundice in patients with unresectable malignant biliary obstruction. Although plastic stents (PSs) were developed earlier, self-expandable metal stents (SEMSs) are now used widely as the initial choice for ERBD in this setting, as SEMSs offer longer patency.However, SEMSs do become occluded in some patients. There are a limited number of reports on the management of occluded SEMS with various results. The aim of this study is to compare the efficacy of ComVi stents SEMSs with uncovered SEMS in subsequent ERBD after the occlusion of initial SEMSs.

Endoscopic placement of self-expandable metallic stents (SEMSs) is the mainstay of palliative measures for alleviating obstructive jaundice secondary to advanced cholangiocarcinoma. Previous meta-analysis showed no significant difference in stent patency between covered and uncovered SEMS, which are currently available. However, information on secondary SEMS insertion is still scarce, and there has been no prospective trial comparing efficacy of secondary stenting between covered and uncovered SEMS for the management of occluded metal stent in malignant biliary obstruction. Previously, only two small retrospective studies addressed this issue. Given the absence of prospective trial on re-intervention for occluded SEMS in malignant biliary obstruction, we aimed to prospectively compare the efficacies and complication rates of secondary ComVi stent (cSEMS) and uSEMS for the management of such condition.

Inclusion Criteria:

• Patients with SEMS occlusion, which was inserted either endoscopically or percutaneously, for the relief of malignant nonhilar biliary obstruction

• Patients in whom the above SEMS had been inserted for no less than 7 days

• Patients with one of the following:

  1. cholangitis (as defined by fever, tenderness in the right upper quadrant or epigastrium, and/or a ≥ twofold increase in the serum bilirubin level above the baseline after initial SEMS insertion)
  2. a ≥ twofold increase in the serum bilirubin level above the baseline after initial SEMS insertion

• Patients in whom the cause of initial ERBD occlusion was identified, such as tumor overgrowth, ingrowth, and/or sludge

• Age ≥ 20 years

Exclusion Criteria:

• Unable to give informed consent
• Patients with sepsis and/or shock not responding to medical treatment or Eastern Cooperative Oncology Group (ECOG) Performance Status 4
• Patients with estimated survival < 4 weeks
• Patients who had undergone curative or palliative surgical intervention
• Hilar or perihilar biliary obstruction
• Patients who had undergone endoscopic nasobiliary drainage,plastic stent insertion, or percutaneous transhepatic biliary drainage prior to second SEMS insertion
• Covered SEMS as initial SEMS
• Migration or food impaction as the cause of initial SEMS occlusion