Endoscopic ultrasound-guided biliary drainage (EUS-BD) has emerged as an important alternative to transpapillary biliary drainage by endoscopic retrograde cholangiopancreatography (ERCP) for malignant biliary obstruction (MBO), especially in cases with failed ERCP. Given the increasing evidences of safety and effectiveness of EUS-BD, EUS-BD as primary biliary drainage has been investigated in clinical trials. However, there are still obstacles that need to be addressed prior to clinical application. In this narrative review, clinical outcomes, hurdles and future perspectives of primary EUS-BD for MBO are discussed.

INTRODUCTION
CLINICAL OUTCOMES OF EUS-BD INCOMPARISON WITH PTBD IN FAILED ERCP
ADVANTAGES OF EUS-BD OVER ERCP-BD
PRIMARY EUS-BD IN COMPARISON WITHERCP-BD
EUS-CDS, EUS-HGS, OR EUS-GBD
HURDLES FOR PRIMARY EUS-BD
FUTURE PERSPECTIVES
CONCLUSION
ORCID
AUTHOR CONTRIBUTION
REFERENCES

• Yousuke Nakai(Department of Internal Medicine, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan) Corresponding author
• Ryunosuke Hakuta(Department of Internal Medicine, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan)
• Ryota Nakabayashi(Department of Internal Medicine, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan)
• Yutaka Shimamatsu(Department of Internal Medicine, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan)
• Nao Otsuka(Department of Internal Medicine, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan)
• Yukiko Takayama(Department of Internal Medicine, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan)