From the Guidelines
Pneumobilia is a condition that typically requires treatment based on its underlying cause, with a focus on managing any associated infection or obstruction, rather than the pneumobilia itself. The presence of air or gas within the biliary tree often indicates an abnormal connection between the biliary system and the gastrointestinal tract, which can be due to various causes such as previous biliary interventions like ERCP, surgical biliary-enteric anastomoses, gallstone ileus, and emphysematous cholecystitis 1.
Diagnosis and Treatment
Diagnosis of pneumobilia is typically made through imaging studies such as abdominal X-rays, ultrasound, CT scans, or MRI, where air appears as dark areas within the biliary tree. Treatment depends on the underlying cause and may involve antibiotics if there is an associated infection, such as cholangitis, with coverage for enteric organisms like E. coli, Klebsiella, and anaerobes, often including combinations such as piperacillin-tazobactam or ciprofloxacin plus metronidazole 1.
Management of Underlying Causes
For conditions like gallstone ileus or biliary-enteric fistulas, surgical intervention may be required. Asymptomatic pneumobilia in patients with previous biliary interventions or surgeries typically requires no treatment as it represents an expected finding. The management of intra-abdominal infections, including those related to biliary obstruction, emphasizes the importance of adequate antimicrobial treatment and biliary decompression to restore biliary drainage in case of obstruction 1.
Recent Guidelines
Recent guidelines, such as those from 2017 for the management of intra-abdominal infections, highlight the role of endoscopic retrograde cholangiopancreatography (ERCP) in the management of biliary obstruction in patients with acute cholangitis, recommending it as the treatment of choice for biliary decompression in patients with moderate/severe acute cholangitis 1. More recent studies and guidelines, such as the 2019 ACR Appropriateness Criteria for radiologic management of biliary obstruction, support the use of ERCP in the management of choledocholithiasis, indicating an increase in its utilization over the years 1.
Key Considerations
The key to managing pneumobilia and its underlying causes is a multidisciplinary approach that considers the severity of the clinical presentation, the availability and feasibility of drainage techniques, and the potential need for surgical intervention. This approach is supported by studies demonstrating the efficacy and safety of endoscopic procedures like ERCP in managing biliary obstruction and reducing morbidity and mortality compared to open surgical drainage 1.
From the Research
Definition and Causes of Pneumobilia
- Pneumobilia is defined as air within the biliary system, usually caused by an abnormal connection between the biliary and gastrointestinal tracts 2, 3.
- The most common conditions associated with pneumobilia include a biliary-enteric surgical anastomosis, an incompetent sphincter of Oddi, or a spontaneous biliary-enteric fistula 3.
Clinical Significance and Complications
- Persistent asymptomatic pneumobilia is a rare occurrence and is generally considered a benign finding on imaging, but it can be associated with increased risk of cholangitis and bacteremia 2.
- Pneumobilia can be a sign of underlying conditions such as cholangitis, which can be life-threatening if left untreated 4.
- Post-ERCP pneumobilia has been associated with increased risk of multiple recurrences of common bile duct stones and acute cholangitis without stone recurrence 5.
Risk Factors and Diagnosis
- Risk factors for pneumobilia include a dilated common bile duct, endoscopic sphincterotomy with moderate or large incisions, and peripapillary diverticulum 5.
- Imaging evaluation of the hepatobiliary system, including computed tomography (CT) scan, endoscopic retrograde cholangiography, and magnetic resonance cholangiopancreatography, can be used to diagnose pneumobilia and underlying conditions 3, 4.
- Biliary drainage procedures and antibiotic treatment may be necessary to manage pneumobilia and underlying conditions such as cholangitis 4, 5.