Randomized Controlled Study to Compare Uncovered Stent Versus Covered Stent as Percutaneous Endoprosthesis for Malignant Biliary Obstruction (JIVROSG-0207).

The objective of this study was to compare the clinical effectiveness of uncovered stent and covered stent as percutaneous endoprosthesis for malignant biliary obstruction of the extrahepatic bile duct. After completion of percutaneous internal and external tube placement for unresectable malignant biliary obstruction, 60 patients were registered and randomly assigned in a 1:1 ratio to an uncovered or covered stent group. Metallic stent placement was performed within 1 week after registration, and an external biliary drainage tube was removed >3 days after stent placement. The primary endpoint was the obstructive jaundice-free survival rate at 24 weeks after registration, and the secondary endpoints were the success rate of percutaneous tube removal and adverse events. The obstructive jaundice-free survival rate at 24 weeks after registration was 13/29 (44.8%, 95% confidence interval [CI]: 28.4%-62.5%) and 15/30 (50.0%, 95% CI: 33.2%-66.8%) in the uncovered and covered stent groups, respectively. The success rate of percutaneous tube removal was 28/29 (96.6%, 95% CI: 82.8%-99.4%) and 30/30 (100%, 95% CI: 90.5%-100%) in the uncovered and covered stent groups, respectively. There were no procedure-related deaths. Twenty-eight adverse events were observed in 21 patients (7 in the uncovered stent group and 14 in the covered stent group). There was no significant difference in the obstructive jaundice-free survival rate at 24 weeks between the 2 groups. Considering the technical difficulty and invasiveness of covered stent placement, the placement of covered stents may not be needed in patients with a short prognosis of <24 weeks.