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

Strasberg-Bismuth Classification and ERCP Findings in Biliary Ductal Injury

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

Understanding the Strasberg-Bismuth Classification

The Strasberg-Bismuth classification categorizes bile duct injuries into:

• 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 ducts 1

Why Type A Injuries Appear Normal on ERCP

Type A injuries present a unique diagnostic challenge because:

1. The main biliary tree architecture remains intact and undamaged
2. The injury involves peripheral structures (cystic duct stump or small peripheral ducts)
3. ERCP primarily visualizes the main biliary tree, not peripheral structures 1

When performing ERCP on a patient with a Type A injury:

• The main biliary ducts will appear completely normal
• The only potential finding may be contrast extravasation from the cystic duct stump or liver bed during the procedure
• Despite normal-appearing ducts, clinical evidence of bile leak may still be present 1

Diagnostic Pitfalls

A critical pitfall in diagnosis is mistaking a normal-appearing biliary tree on ERCP as absence of injury when clinical suspicion for bile leak exists. Type A injuries may not be immediately apparent on ERCP and can present days after surgery with:

• Bile leak
• Biliary peritonitis
• Biloma formation
• Elevated liver function tests and inflammatory markers 1

Diagnostic Algorithm for Suspected Bile Duct Injury

1. For suspected Type A injuries:

   • ERCP is both diagnostic and therapeutic
   • Look for contrast extravasation despite normal biliary anatomy
   • Success rates approach 90% for diagnosis and treatment 1

2. For suspected Types B-E injuries:

   • ERCP alone may be insufficient
   • Additional imaging with MRCP or PTC is necessary for complete evaluation
   • These injuries will show abnormal findings on ERCP 1, 2

All other injury types (B through E) will demonstrate abnormal findings on ERCP:

• Type B: Occlusion of part of biliary tree will be visible
• Type C: Missing right posterior sectoral duct
• Type D: Visible lateral defect in major bile ducts
• Type E: Major structural abnormalities of common hepatic or bile ducts 1, 3

Remember that while ERCP is valuable for diagnosis and treatment, it has limitations in visualizing injuries above the level of obstruction, which is why additional imaging modalities may be necessary for complete evaluation of major bile duct injuries.