What percentage of liver volume should be preserved when draining the liver in hilar cholangiocarcinoma involving the right system?

Drainage Volume in Hilar Cholangiocarcinoma Involving the Right System

For hilar cholangiocarcinoma involving the right system, you should drain at least 50% of the functional liver parenchyma, specifically targeting the future liver remnant (left side) that will remain after planned right hepatectomy. 1

Preoperative Drainage Strategy

When to Drain

Preoperative biliary drainage is indicated when: 1

• Bilirubin >50 μmol/L (especially >218.75 μmol/L based on recent meta-analysis) 1
• Cholangitis or hepatobiliary sepsis is present 1
• Extensive surgery planned (>50% liver parenchyma resection) 1
• Portal vein embolization is needed 1
• Patient has malnutrition or significant comorbidities 1

Critical caveat: For planned left lobectomy, preoperative drainage is NOT recommended as it increases infection-related morbidity. 1 However, for right-sided involvement requiring right or extended right hepatectomy, drainage of the left system (future liver remnant) is essential.

Specific Volume Requirements

The most recent French guidelines (2024) provide the clearest directive: drain at least 50% of functional hepatic parenchyma while avoiding atrophic segments. 1 This represents a shift from older thinking, as recent data suggest draining >50% of liver volume produces more favorable long-term results. 2, 3

For right-sided hilar cholangiocarcinoma (Bismuth type IIIA or IV):

• Drain the left hepatic system selectively (the future liver remnant after right hepatectomy) 4, 3
• Ensure drainage of all opacified segments to prevent cholangitis 1, 3
• Exclude atrophic segments identified on CT scan from drainage planning, as these increase cholangitis risk without benefit 1, 3

Technical Approach

Use removable plastic stents for preoperative drainage rather than metal stents, as this preserves surgical options. 1 The 2024 French guidelines strongly recommend this approach with Grade 1+ evidence. 1

Selective (unilateral) drainage of the future liver remnant is generally sufficient. 4 However, if cholangitis develops after unilateral drainage or hyperbilirubinemia resolves slowly, consider total biliary drainage. 4

Duration and Bilirubin Targets

Minimize the duration of preoperative biliary drainage to reduce infectious complications, which occur in up to 74% of cases. 5 The optimal preoperative bilirubin level remains debated, but aim for <200 μmol/L before major hepatectomy. 1, 5, 6

Key Contraindications

Do NOT perform routine biliary drainage in these situations: 1

• Cholestasis without jaundice 1
• Before complete staging (CT/MRI) is performed, as drainage may compromise resectability assessment 1
• Bilirubin <50 μmol/L without other indications 1

Common Pitfalls to Avoid

1. Draining the wrong side: For right-sided tumors requiring right hepatectomy, drain the LEFT system (future remnant), not the diseased right side 4, 3

2. Incomplete drainage of opacified segments: All segments visualized during cholangiography must be drained to prevent life-threatening cholangitis 1, 3

3. Using metal stents preoperatively: This compromises surgical options and increases complications 1

4. Draining atrophic segments: These contribute to cholangitis without functional benefit 1, 3

5. Prolonged drainage duration: The recent meta-analysis shows PBD increases morbidity, infection, transfusion requirements, and hospital stay, so minimize the interval between drainage and surgery 1

Risk-Benefit Considerations

The 2025 meta-analysis reveals important trade-offs: 1

• PBD reduces hepatic insufficiency (OR=0.38) 1
• BUT increases long-term mortality (OR=1.90), morbidity (OR=1.47), postoperative infection (OR=2.46), and cholangitis (OR=6.40) 1

These risks are acceptable when bilirubin >218.75 μmol/L, portal vein embolization is planned, or malnutrition exists, as the benefit of preventing hepatic insufficiency outweighs the infectious risks in these specific scenarios. 1