What is the diagnostic test for a 3-week-old baby presenting with features of biliary atresia and no visible gallbladder (biliary atresia is a condition where the bile ducts are blocked or absent)?

From the Guidelines

The diagnostic test for a 3-week-old baby presenting with features of biliary atresia and no visible gallbladder is intraoperative cholangiogram, as it directly visualizes the biliary anatomy and confirms the diagnosis by demonstrating absence or obstruction of bile ducts. For a 3-week-old baby presenting with features of biliary atresia and absence of gallbladder, intraoperative cholangiogram is the definitive diagnostic test. This procedure involves direct injection of contrast material into the biliary tree during surgery, allowing visualization of the biliary anatomy and confirmation of biliary atresia by demonstrating absence or obstruction of bile ducts. While liver biopsy can show histological changes consistent with biliary atresia (such as bile duct proliferation, portal fibrosis, and bile plugs), it is not as definitive as intraoperative cholangiogram, which directly visualizes the biliary system 1.

Key Points to Consider

• Intraoperative cholangiogram is typically performed during the Kasai procedure (hepatoportoenterostomy), which is the surgical treatment for biliary atresia.
• Early diagnosis and intervention before 60 days of life significantly improves outcomes, as biliary atresia leads to progressive liver fibrosis and cirrhosis if left untreated 1.
• The Kasai procedure can result in prolonged survival in as many as 70% of infants if performed within the first 2 months of life by an experienced surgeon.
• Delayed diagnosis beyond 3 months significantly reduces the success of the Kasai procedure.

Diagnostic Approach

• Intraoperative cholangiogram is the most accurate diagnostic test for biliary atresia, as it provides direct visualization of the biliary anatomy.
• Liver biopsy can be used to support the diagnosis, but it is not as definitive as intraoperative cholangiogram.
• Other diagnostic tests, such as ultrasound and MRI, may be used to support the diagnosis, but they are not as accurate as intraoperative cholangiogram.

From the Research

Diagnostic Tests for Biliary Atresia

The diagnostic tests for a 3-week-old baby presenting with features of biliary atresia and no visible gallbladder include:

• Ultrasonography (US) as the main tool for pre- and neonatal diagnosis 2
• Key prenatal features such as non-visualisation of the gallbladder, cyst in the liver hilum, heterotaxy syndrome, and irregular gallbladder walls 2
• Postnatal imaging features with high specificity when present, including triangular cord sign and abnormal gallbladder 2
• Percutaneous transhepatic cholecysto-cholangiography (PTCC) and liver biopsy as less invasive methods to exclude biliary atresia 3
• Laparoscopic fluorescence cholangiography (LFC) as a potential diagnostic tool with advantages of simplicity and no radiation damage 4

Imaging Techniques

Imaging techniques used in the diagnosis of biliary atresia include:

• Ultrasound (US) with high specificity, although a normal US examination does not rule out biliary atresia 5
• Magnetic resonance (MR) cholecystopancreatography and hepatobiliary scintigraphy, which are not useful for the diagnosis of biliary atresia 5
• PTCC and liver biopsy, which can effectively exclude biliary atresia with acceptable morbidity 3
• LFC, which appears as a specific pattern in biliary atresia and may be used for intraoperative diagnosis 4

Diagnostic Challenges

The diagnosis of biliary atresia is challenging due to:

• Overlapping clinical and imaging features with other causes of cholestasis in newborns 6, 5, 2
• No single method for diagnosing biliary atresia, requiring a combination of imaging techniques and clinical evaluation 5, 2
• Need for prompt evaluation to exclude biliary atresia and other treatable hepatic conditions 3