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

Type A Bile Duct Injuries Will Appear Normal on ERCP in the Strasberg-Bismuth Classification

Type A bile duct injuries will appear normal on ERCP because the main biliary tree structure remains intact while the injury involves peripheral structures that may not be directly visualized during the procedure. 1

Understanding the Strasberg-Bismuth Classification

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 Injuries Appear Normal on ERCP

Type A injuries present a unique diagnostic challenge for several reasons:

• The main biliary tree structure remains intact and appears normal on cholangiography 1
• The injury involves peripheral structures (cystic duct stump or ducts of Luschka) that may not be directly visualized during ERCP 1
• ERCP will show a normal biliary tree with no obstruction or strictures 2

Diagnostic Features of Type A Injuries

Despite normal appearance of the main biliary tree 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

Comparison with Other Types of Bile Duct Injuries

Unlike Type A injuries:

• Type B, C, and D injuries will show abnormalities on ERCP as they involve occlusion, transection, or lateral injury to bile ducts 1
• Type E injuries show major abnormalities on ERCP as they involve major injury to common hepatic or common bile duct 1

Management Implications

The normal appearance on ERCP has important management implications:

• For Type A injuries, if a drain is placed after surgery and a bile leak is noted, observation with drainage is the initial approach 1
• If the leak persists, ERCP with biliary sphincterotomy and stent placement becomes necessary 1
• ERCP with stenting is highly effective for Type A injuries, with success rates approaching 90% 1, 2

Diagnostic Limitations and Alternative Imaging

When ERCP findings are normal but clinical suspicion for bile leak remains high:

• MRCP combined with hepatocyte-specific contrast agents can provide functional assessment of the biliary tree with accuracy close to 100% for detecting bile leaks 3
• Hepatobiliary scintigraphy may be more sensitive and specific than US or CT in detecting bile leaks 3

Clinical Pitfalls to Avoid

• Do not rule out a bile duct injury solely based on normal ERCP appearance of the main biliary tree
• Remember that Type A injuries may only be detected by contrast extravasation during ERCP, not by structural abnormalities
• Consider additional imaging modalities when ERCP findings are normal but clinical suspicion for bile leak remains high

In conclusion, Type A injuries in the Strasberg-Bismuth classification will appear normal on ERCP because the main biliary tree structure remains intact while the injury involves peripheral structures.