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

Type A Bile Duct Injury Appears Normal on ERCP in Strasberg-Bismuth Classification

Type A bile duct injuries 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 Strasberg-Bismuth Classification

The Strasberg-Bismuth classification is one of the most widely used systems for categorizing bile duct injuries (BDIs) that occur during laparoscopic cholecystectomy. The classification includes:

• 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 Appears Normal on ERCP

Type A injuries present a unique diagnostic challenge because:

1. The main biliary tree structure remains completely intact
2. The injury involves peripheral structures (cystic duct stump or minor ducts in liver bed)
3. These peripheral structures are not part of the main biliary tree that is visualized during ERCP 1

During ERCP, contrast is injected into the main biliary system, which fills the common bile duct, common hepatic duct, and major intrahepatic ducts. Since Type A injuries don't affect these structures, the cholangiogram appears normal.

Diagnostic Features of Type A Injuries

Although the main biliary tree appears normal on ERCP in Type A injuries, they can still be detected by:

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

Comparison with Other Types

Unlike Type A, other types of bile duct injuries will show abnormalities on ERCP:

• Type B, C, D: Show abnormalities on ERCP as they involve occlusion, transection, or lateral injury to bile ducts
• Type E (1-5): Show major abnormalities on ERCP as they involve major injury to common hepatic or common bile duct 1

Management of Type A Injuries

For Type A injuries that appear normal on ERCP:

• Initial approach: Observation with drainage if a drain is already in place
• If leak persists: ERCP with biliary sphincterotomy and stent placement becomes mandatory
• Success rate of ERCP with stenting approaches 90% for Type A injuries 1

Clinical Pitfalls and Caveats

1. Don't mistake a normal ERCP for absence of injury when clinical signs of bile leak are present
2. Type A injuries may require additional imaging modalities like MRCP or CT for complete evaluation
3. Despite appearing normal on ERCP, Type A injuries still require proper management to prevent complications like biliary peritonitis or biloma formation
4. Even though the main biliary tree appears normal, therapeutic ERCP with sphincterotomy and stenting is still highly effective for managing these injuries

The key to understanding Type A injuries is recognizing that while the main biliary tree remains intact and appears normal on ERCP, the peripheral injury can still cause significant clinical problems requiring prompt diagnosis and management.