What is the role of the TG (Tokyo Guidelines) 13 classification in managing acute cholangitis?

Role of TG13 Classification in Managing Acute Cholangitis

The Tokyo Guidelines 2013 (TG13) classification is essential for the diagnosis, severity assessment, and treatment planning of acute cholangitis, guiding appropriate interventions based on disease severity to reduce mortality and morbidity. 1

Diagnostic Criteria in TG13

• TG13 allows for diagnosis of acute cholangitis when Charcot's triad (fever/chills, abdominal pain, and jaundice) is present 2
• When the complete triad is absent, diagnosis can still be made with laboratory data and imaging findings supporting inflammation and biliary obstruction 2
• The TG13 diagnostic criteria have improved detection rates, with studies showing 90.0% of clinically suspected cases meeting TG13 criteria compared to 79.4% with previous TG07 criteria 3

Severity Assessment System

TG13 classifies acute cholangitis into three grades based on severity 1:

• Grade I (Mild): Responds to initial medical treatment with improved clinical findings 2
• Grade II (Moderate): No organ dysfunction but does not respond to initial medical treatment; requires early biliary drainage 2
• Grade III (Severe): Presence of organ dysfunction; requires urgent biliary drainage and intensive care 2

This severity grading directly correlates with mortality rates:

• Grade III: 5.1% mortality
• Grade II: 2.6% mortality
• Grade I: 1.2% mortality 3

Clinical Application of TG13 Classification

Imaging Guidance

• TG13 recommends appropriate imaging modalities based on clinical context 1
• EUS and MRCP are preferred for CBD stone detection with high sensitivities (93% and 85%) and specificities (96% and 93%) 1
• Initial ultrasound is recommended despite lower sensitivity (25-63%) due to wide availability 1

Treatment Recommendations Based on Severity

1. Antibiotic Management:

   • Immediate broad-spectrum antibiotics covering Gram-negative enteric bacteria 1
   • For septic shock: administer within 1 hour
   • For non-shock cases: administer within 4 hours 1
   • Duration depends on drainage success - can be limited to 3 days with successful drainage 1

2. Biliary Drainage Strategy by Grade:

   • Grade III (Severe): Urgent biliary drainage with organ support 4
   • Grade II (Moderate): Early biliary drainage (significantly reduces mortality from 3.7% to 2.0%) 3
   • Grade I (Mild): Drainage only if initial antibiotic therapy is ineffective 4

3. Drainage Method Selection:

   • Endoscopic transpapillary biliary drainage should be first-line therapy 5
   • Percutaneous transhepatic drainage or EUS-guided drainage as alternatives 1
   • Surgical drainage should be avoided in severe cholangitis 1

Limitations and Evolving Aspects

• Some Grade II cases requiring early drainage may be underestimated as Grade I 6
• Additional factors beyond TG13 criteria (like obesity) may influence severity assessment 1
• A proposed scoring system using five predictors (BUN >20 mg/dL, SIRS presence, platelet count <120,000/μL, albumin <3.0 g/dL, age ≥75) may better identify high-risk patients 6
• Newer drainage techniques like balloon enteroscopy-assisted ERCP and EUS-guided biliary drainage are increasingly recognized in updated guidelines 5

Procedural Considerations

• Endoscopic sphincterotomy (EST) is not routinely required for biliary drainage alone 5
• For concomitant bile duct stones, consider:
  • Single-session stone removal with EST in mild/moderate cases 5
  • Two-session approach for difficult stones (large or multiple) 5
  • Endoscopic papillary dilation instead of EST in patients with coagulopathy 5