# Endoscopic Stenting for Unresectable Malignant Hilar Biliary Obstruction: Where Do We Stand Today? A Narrative Review

## TL;DR

This review discusses the best ways to treat blocked bile ducts in advanced liver and bile cancers using endoscopic stents, focusing on improving patient outcomes and quality of life.

## Contribution

The paper provides a comprehensive overview of current endoscopic stenting strategies and emerging techniques for treating unresectable malignant hilar biliary obstruction.

## Key findings

- Endoscopic ultrasound-guided drainage is emerging as a promising alternative to traditional transpapillary methods.
- Uncovered metal stents remain standard but face limitations in reintervention, prompting reevaluation of stent types and techniques.
- Prospective studies are needed to establish standardized guidelines for optimal stent strategies in unresectable cases.

## Abstract

Blockage of the bile ducts at the point where they meet inside the liver can occur in patients with advanced cancers of the bile duct, gallbladder, pancreas, or liver. This condition causes yellowing of the skin, itching, and infection, and it requires drainage of bile to relieve symptoms and improve liver function. When surgery is not possible, endoscopic placement of small tubes called stents can reopen the blocked ducts. Many different stent types and techniques have been developed, but the best approach is still debated because the anatomy in this region is very complex. This review summarizes the current knowledge about how to select the best drainage strategy, including which part of the liver should be drained and which stent type is most effective. It also describes new techniques such as drainage guided by ultrasound from inside the body. The findings highlight the need for treatments that not only last longer and are easier to repeat but also improve comfort and quality of life for people living with advanced disease. The review aims to help doctors choose the safest and most effective treatment for each patient.

Malignant hilar biliary obstruction (MHBO) is a complex clinical condition commonly observed in individuals with advanced cholangiocarcinoma and other hepatobiliary malignancies. Endoscopic stenting remains the primary palliative intervention for unresectable cases; however, the optimal strategy has not been clearly defined owing to the anatomical intricacies of the hilar region and the heterogeneity of disease presentation. This narrative review summarizes current evidence and ongoing debates on functional liver volume-based drainage, unilateral versus bilateral stenting, stent type selection, and above-the-papilla approaches. In addition, we highlight recent progress in endoscopic ultrasound-guided biliary drainage as a promising alternative or complementary approach when conventional transpapillary drainage proves inadequate. With recent advances in systemic therapies, including immunotherapy, patient survival has improved, underscoring the need for durable, reintervention-friendly stent strategies. Although uncovered metal stents have long been regarded as the standard for unresectable cases, their limitations in reintervention have prompted renewed consideration of both stent type and drainage technique. Robust prospective studies remain essential to establish standardized, evidence-based guidelines that optimize patient benefit and improve long-term outcomes in unresectable MHBO.