Biliary atresia (BA) is life-threatening and is only found in newborn babies. It is characterised by an obstruction of the bile ducts, which leads to a build-up of toxic bile (cholestasis). If left untreated, cholestasis in BA damages the liver, which rapidly undergoes cirrhotic remodelling.

Causes of BA

The causes of BA are still unknown. Genetic and autoimmune factors, environmental influences or infections could play a role. The bile ducts show inflammation and scarring inside and outside the liver. If left untreated, the disease is always fatal before the age of two or three. Kasai surgery can temporarily buy time and in some cases also halt the progression of the disease. However, a liver transplant is often necessary and life-saving.

Symptoms

Newborns initially show no recognisable symptoms. The disease only slowly becomes recognisable in the first six weeks after birth. Symptoms such as jaundice (icterus) due to bile stasis, lack of bile secretion into the intestine (acholia) with pale or whitish faeces, itching, dark yellow urine and sometimes an enlarged liver occur. The lack of bile flow into the intestine can disrupt the absorption of fats and fat-soluble vitamins, which can lead to growth disorders and vitamin deficiency.

Diagnosis

If there are signs of BA, the conjugated bilirubin in the blood is determined, as are the liver values gamma-GT, GOT and GPT. Blood tests often show a deficiency of fat-soluble vitamins, which should be substituted orally. Further examinations, such as ultrasound, liver biopsy or ERCP, are necessary to recognise a BA. Visualisation of the bile ducts is also required to arrive at a conclusive diagnosis.

Treatment

Treatment is surgical and involves a Kasai operation at the earliest possible stage. This involves opening the blind bile ducts in the liver and suturing them with a loop of small intestine to allow bile to flow out. In addition, ursodeoxycholic acid (UDCA) is administered after the operation to increase the flow of bile. New drugs are being researched in studies. In many cases, however, BA is recognised too late, resulting in liver damage (usually cirrhosis) that necessitates a liver transplant in childhood. Biliary atresia affects around 270 children in Europe every year and is the most common cause of liver transplants in childhood and adolescence.