In Bismuth II-IV hilar cholangiocarcinoma patients with a predicted survival of longer than 3 months, metallic stent performance is superior to plastic stenting for palliation with respect to outcomes and cost-effectiveness. However, the optimal stent type and the extent of drainage are issues that remain to be definitively decided. The optimal endoscopic management strategy is contentious. The investigators conduct the present study to prospectively in multi-centers compare unilateral (single) with bilateral (multiple) deployment in inoperable malignant biliary obstructions to clarify the clinical outcomes of these two deployment methods using metallic stents.

In Bismuth II-IV hilar cholangiocarcinoma patients with a predicted survival of longer than 3 months, metallic stent performance is superior to plastic stenting for palliation with respect to outcomes and cost-effectiveness.

However, the optimal stent type and the extent of drainage are issues that remain to be definitively decided. The optimal endoscopic management strategy is contentious.

The investigators conduct the present study to prospectively in multi-centers compare unilateral (single) with bilateral (multiple) deployment in inoperable malignant biliary obstructions to clarify the clinical outcomes of these two deployment methods using metallic stents.

First as an unilateral or bilateral stent will be deployed according to criteria.

In bilateral group, stent-in-stent or side-by-side deployment will be included.

Inclusion Criteria:

• age > 18 years
• inoperable hilar malignancy

Exclusion Criteria:

• age under 18 years
• uncontrolled coagulopathy
• inability to provide informed consent