Which type of Strasberg Bismuth classification for biliary (bile) ductal injury will appear normal on Endoscopic Retrograde Cholangiopancreatography (ERCP)?

Strasberg-Bismuth Classification: Type A Injuries Appear Normal on ERCP

Type A bile duct injuries will appear normal on ERCP because the main biliary tree structure remains intact while the leak occurs from peripheral ducts or the cystic duct stump. 1

Understanding Type A Injuries and ERCP Findings

Type A injuries in the Strasberg-Bismuth classification represent bile leaks from:

• Cystic duct stump
• Minor ducts in the liver bed (ducts of Luschka)

These injuries present a unique diagnostic challenge because:

• The main biliary tree structure remains intact
• The biliary anatomy appears normal on cholangiography
• The injury is only detected by contrast extravasation from the leak site during ERCP 1

Characteristics of Other Strasberg-Bismuth Classifications on ERCP

Unlike Type A injuries, other types show abnormal findings on ERCP:

• Type B: Shows occlusion of part of the biliary tree, visible as a lack of filling of segments of the intrahepatic biliary system
• Type C: Demonstrates transection without ligation of aberrant right hepatic duct, visible as contrast extravasation without opacification of segments
• Type D: Shows lateral injury to major bile ducts, visible as contrast leakage from the side of major ducts
• Type E (1-5): Reveals major injury to common hepatic or common bile ducts with varying levels of stricture or complete transection 1

Clinical Implications and Management

Type A injuries account for a significant proportion of bile duct injuries (46.4% in one study) 2. Despite appearing normal on ERCP, these injuries can be effectively managed through:

1. Initial observation with drainage if a drain is already in place
2. ERCP with biliary sphincterotomy and stent placement if the leak persists
3. Success rates approaching 90% with endoscopic management 1

Diagnostic Approach for Suspected Type A Injuries

When ERCP findings show normal biliary anatomy but clinical suspicion for bile leak remains high:

• MRCP with hepatocyte-specific contrast agents can provide functional assessment with nearly 100% accuracy
• Hepatobiliary scintigraphy may be more sensitive than ultrasound or CT in detecting bile leaks 1

Common Pitfalls in Diagnosis

• Relying solely on ERCP appearance without dynamic contrast studies may miss Type A injuries
• Normal biliary tree appearance may falsely reassure clinicians despite ongoing bile leak
• Additional imaging modalities are essential when clinical suspicion remains high despite normal ERCP findings 1

The key distinguishing feature of Type A injuries is that they represent peripheral leaks with preserved main biliary tree anatomy, making them the only type to appear normal on ERCP while still causing clinical bile leak symptoms.