What type of biliary ductal injury appears normal on Endoscopic Retrograde Cholangiopancreatography (ERCP) and is not a Type B injury?

Type A Biliary Ductal Injury Appears Normal on ERCP

Type A biliary ductal injuries (bile leaks from cystic duct stump or minor ducts in liver bed) appear normal on ERCP because the main biliary tree structure remains intact, yet they represent the most common type of post-cholecystectomy bile leak. 1

Characteristics of Type A Biliary Injuries

• Definition: Type A injuries in the Strasberg-Bismuth classification involve bile leaks from:

  • Cystic duct stump
  • Minor ducts in the liver bed (ducts of Luschka)
  • No injury to major bile ducts 1

• Diagnostic Challenge: These injuries present a unique challenge because:

  • The main biliary tree structure remains intact
  • Cholangiogram appears normal on ERCP
  • Diagnosis is made by contrast extravasation from the leak site rather than structural abnormality 1

Diagnostic Features on ERCP

• Normal Appearance: The biliary tree appears structurally normal and intact

• Diagnostic Clue: Contrast extravasation may be seen from:

  • Cystic duct stump
  • Small ducts in liver bed
  • This extravasation is the only abnormal finding 2

• Classification Distinction: Unlike Type B injuries (which show occlusion of part of the biliary tree), Type A injuries maintain normal biliary anatomy with preserved ductal continuity 1

Clinical Presentation

• Bile leak with peritonitis
• Biloma formation
• Elevated liver function tests
• Inflammatory markers 1

Management Approach

1. Initial Management:

   • Observation with drainage if a drain is already in place
   • Monitoring for spontaneous resolution 2, 1

2. If leak persists:

   • ERCP with biliary sphincterotomy and stent placement becomes mandatory
   • Success rates approaching 90% for Type A injuries 1
   • Stent placement reduces transpapillary pressure gradient to facilitate bile flow through papilla rather than leak site 2

3. Follow-up:

   • Stents typically left in place for 4-8 weeks
   • Removal after cholangiography confirms resolution of leakage 2

Important Distinctions from Other Types

• Not Type B: Type B injuries show occlusion of part of the biliary tree, while Type A shows normal biliary anatomy
• Not Type C: Type C involves transection of aberrant right hepatic duct
• Not Type D: Type D involves lateral injury to major bile ducts
• Not Type E: Type E involves major injury to common hepatic or common bile ducts 1

Type A injuries are the most amenable to endoscopic management with excellent outcomes, whereas other types often require more complex interventions or surgical repair.