What definitive investigation is used to confirm a diagnosis of biliary atresia?

The definitive investigation used to confirm a diagnosis of biliary atresia is a cholangiogram. This imaging technique provides a clear visualization of the biliary tree and assesses the patency of the bile ducts.

In biliary atresia, the bile ducts are absent or obstructed, which can lead to cholestasis and liver damage if not diagnosed and treated early. A cholangiogram can reveal the degree of biliary obstruction or absence, which is critical in differentiating biliary atresia from other conditions that may present with similar symptoms, such as neonatal hepatitis.

While liver function tests are valuable in assessing liver status and function, they do not provide specific information about the structure of the bile ducts. An X-ray is generally not used for this purpose, and hepatic angiography focuses more on blood vessels rather than the biliary system. Therefore, the cholangiogram stands out as the key investigation for confirming biliary atresia.