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

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

Type A injuries (bile leaks from cystic duct stump or minor ducts in the liver bed) will appear normal on ERCP because the main biliary tree structure remains intact. 1

Understanding Strasberg-Bismuth Classification and ERCP Findings

The Strasberg-Bismuth classification categorizes bile duct injuries (BDIs) into five main types:

• Type A: Bile leaks from cystic duct stump or minor ducts in liver bed (ducts of Luschka)
• Type B: Occlusion of part of the biliary tree
• Type C: Transection without ligation of aberrant right hepatic duct
• Type D: Lateral injury to major bile ducts
• Type E (1-5): Major injury to common hepatic or common bile duct

Why Type A Appears Normal on ERCP

Type A injuries present a unique diagnostic challenge because:

1. The main biliary tree structure remains intact and appears normal on cholangiography 1
2. The injury involves peripheral structures that may not be directly visualized during ERCP 1
3. The leak occurs from the cystic duct stump or minor ducts in the liver bed, which are not part of the main biliary tree that is visualized during ERCP 1

Diagnostic Considerations

Despite normal appearance on ERCP, Type A injuries can be detected by:

• Contrast extravasation from the cystic duct stump or liver bed during ERCP 1
• Clinical presentation with bile leak, biliary peritonitis, or biloma formation 1
• Elevated liver function tests and inflammatory markers 1

It's crucial not to mistake a normal-appearing biliary tree on ERCP as absence of injury when clinical suspicion for bile leak exists, as Type A injuries may not be immediately apparent and can present days after surgery 1.

Management of Type A Injuries

When Type A injuries are suspected:

1. Initial observation with drainage if a drain is already in place 2
2. If the leak persists, ERCP with biliary sphincterotomy and stent placement becomes mandatory 2
3. ERCP with stenting is highly effective for Type A injuries, with success rates approaching 90% 1, 3

The goal of endoscopic therapy is to reduce the transpapillary pressure gradient to facilitate preferential bile flow through the papilla as opposed to the site of the leak, providing time for the biliary tree injury to heal 2.

Comparison with Other Types of Injuries

Unlike Type A injuries:

• Type B, C, D injuries: Will show abnormalities on ERCP as they involve occlusion, transection, or lateral injury to bile ducts
• Type E injuries: Show major abnormalities on ERCP as they involve major injury to common hepatic or common bile ducts 2, 1

For these more complex BDI types (B-E), additional imaging modalities like MRCP or PTC may be necessary for complete evaluation, as ERCP alone may not be sufficient 1.