Combination of endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography-guided biliary drainage in malignant hilar biliary obstruction.

Adequate biliary drainage (BD), defined as more than 50% of liver volume drained, is an ideal BD method in patients with advanced and unresectable malignant hilar biliary obstruction (MHBO). Endoscopic retrograde cholangiopancreatography (ERCP) with multi-segmental BD is technically challenging. ERCP with percutaneous biliary drainage (PTBD) or PTBD alone has cumbersome maintenance of PTBD line and external bag. The utility of EUS-guided BD (EUS-BD) has risen significantly over last 5 years mostly in the clinical setting of distal bile duct obstruction. Information on EUS-BD for malignant hilar biliary obstruction (MHBO) is thus far limited to only two small studies. This review suggests a new concept of a combination of ERCP and EUS-BD (CERES) for BD in MHBO as a primary BD method whereby ERCP with a single self-expandable metal stent (SEMS) is placed into either the right or the left intrahepatic bile duct (IHD). If SEMS is placed in the right biliary system, EUS-guided hepaticogastrostomy (EUS-HGS) can subsequently be carried out. However, if the stent is placed into the left biliary system, EUS-guided hepaticoduodenostomy (EUS-HDS) is done. For MHBO with non-functioning right lobe of the liver, EUS-HGS is carried out after failed ERCP, or primary HGS can be carried out in the left lobe of liver. For MHBO with non-functioning left lobe of the liver, EUS-HDS is carried out after failed transpapillary stenting of the right lobe by ERCP. Based on our experience, CERES is promising as it can fulfil gaps of both PTBD and ERCP by allowing internal drainage that can circumvent the inconvenience associated with PTBD and offer higher technical success rate compared to ERCP with bilateral SEMS placement.