Type A Injuries in Strasberg-Bismuth Classification Will Appear Normal on ERCP
In the Strasberg-Bismuth classification for biliary ductal injury, Type A injuries will appear normal on ERCP because they involve peripheral bile leaks from the cystic duct stump or minor ducts in the liver bed (ducts of Luschka) while the main biliary tree structure remains intact. 1
Understanding Type A Injuries
Type A injuries are characterized by:
- Bile leaks from the cystic duct stump or minor ducts in the liver bed (ducts of Luschka)
- Intact main biliary tree structure
- Normal appearance of the main biliary tree on cholangiography
- Peripheral nature of the injury that may not be directly visualized during ERCP
These injuries present a unique diagnostic challenge because while the main biliary tree appears normal on ERCP, the actual injury involves peripheral structures that may only be detected by contrast extravasation during the procedure 1.
Diagnostic Features of Different Strasberg-Bismuth Types on ERCP
| Type | Description | ERCP Appearance |
|---|---|---|
| A | Bile leaks from cystic duct stump or minor ducts | Normal main biliary tree with possible contrast extravasation |
| B | Occlusion of part of biliary tree | Abnormal - non-filling of occluded segment |
| C | Transection of aberrant right hepatic duct | Abnormal - non-visualization of sectoral duct |
| D | Lateral injury to major bile ducts | Abnormal - contrast extravasation from main duct |
| E (1-5) | Major injury to common hepatic/bile duct | Abnormal - major structural abnormalities |
Clinical Implications
The normal appearance of the biliary tree on ERCP in Type A injuries has important clinical implications:
- May lead to false reassurance if only the main biliary tree is assessed
- Requires careful inspection for contrast extravasation during the procedure
- Necessitates correlation with clinical presentation (bile leak, biliary peritonitis, biloma)
- Often requires additional diagnostic modalities for complete evaluation
Management Approach for Type A Injuries
Despite appearing normal on initial ERCP assessment, Type A injuries still require proper management:
- Initial observation with drainage if a drain is already in place
- If bile leak persists, ERCP with biliary sphincterotomy and stent placement becomes mandatory
- ERCP with stenting is highly effective for Type A injuries, with success rates approaching 90% 1
Diagnostic Pitfalls to Avoid
When evaluating potential biliary injuries:
- Don't rely solely on the appearance of the main biliary tree
- Look specifically for contrast extravasation during ERCP
- Consider complementary imaging like MRCP with hepatobiliary contrast agents for better visualization of bile leaks
- Remember that normal-appearing ducts on ERCP don't exclude Type A injuries
Conclusion
Type A injuries in the Strasberg-Bismuth classification present with a normal-appearing main biliary tree on ERCP, making them unique among the classification types. This normal appearance occurs because the injury involves peripheral structures while the main biliary architecture remains intact.