From the Research
Intrahepatic pneumobilia is a radiological finding that requires investigation to determine its clinical significance and appropriate management, and the most recent study 1 suggests that patients with post-ERCP pneumobilia have increased risk of multiple recurrences of common bile duct stones and acute cholangitis without stone recurrence. Intrahepatic pneumobilia refers to the presence of air or gas within the bile ducts inside the liver, and this condition typically indicates an abnormal communication between the biliary tract and the gastrointestinal tract.
Common Causes
The most common causes include:
- Previous biliary interventions (such as ERCP or biliary surgery)
- Sphincterotomy
- Biliary stent placement
- Pathological conditions like gallstone disease with passage of stones, biliary-enteric fistulas, or infections with gas-forming organisms Management depends on the underlying cause, and if pneumobilia is found incidentally in an asymptomatic patient with a history of biliary intervention, no specific treatment is needed. However, if it occurs with symptoms like fever, abdominal pain, or jaundice, urgent evaluation is necessary to identify and treat the underlying cause, which may include:
- Antibiotics for cholangitis
- ERCP for stone removal
- Surgery for fistula repair Diagnostic workup typically includes imaging studies like:
- Ultrasound
- CT scan
- MRCP to visualize the biliary tree and identify the source of the air The addition of T1-weighted gradient-echo in-phase images to standard MRCP sequences improves the detection and differentiation of hepatolithiasis and intrahepatic pneumobilia, as shown in the study 2. Independent risk factors for pneumobilia include peripapillary diverticulum, a dilated CBD (>1 cm), and endoscopic sphincterotomy with moderate and large incisions, as identified in the study 1.
Key Points
- Pneumobilia itself is not a disease but rather a radiological finding that requires investigation to determine its clinical significance and appropriate management
- The study 3 highlights the importance of distinguishing pneumobilia from air in the portal venous system using computed tomography (CT) scan
- The study 4 discusses the use of hepatic MR imaging to identify pneumobilia, which causes a susceptibility artifact and appears as a signal void on a dual echo gradient MR sequence
- The study 5 reviews the surgical approaches for managing gallstone ileus, a rare disease that can result in pneumobilia, and emphasizes the importance of early intervention due to the high mortality rate associated with this condition.