In the first few days after birth, almost every second newborn has a more or less yellowish skin color. This yellow coloration (icterus) of the skin, which occasionally also occurs on the conjunctiva of the eyes, usually disappears within two weeks. This is referred to as "transient (passagere) jaundice" of the newborn (icterus neonatorum). In exceptional cases, however, this jaundice can also be the first symptom of a serious illness, so that further diagnostics must be started in good time. This is particularly important in the case of a suspected diagnosis of "biliary atresia", as this is one of the few liver diseases where the chances of a favorable course of the disease depend on timely diagnosis and the associated surgery. However, the problem of biliary atresia is complex. On the one hand, the disease is very rare, occurring in only one in approximately 18,000 newborns. In Germany, we therefore expect around 35 to 40 cases per year. As most of these children require a liver transplant sooner or later, biliary atresia is now the most common cause of this particularly critical intervention in childhood.

 

About the development of biliary atresia

The first reports of newborns with biliary atresia date back to the 19th century. At that time, all children died within 2 years. Fortunately, things are different today, although we still do not know when and what actually causes biliary atresia. Until around 1970, it was assumed that it was a congenital disease that developed in the womb. Today we know that inflammation of all the bile ducts leads to rapid progressive destruction of the entire liver. Unfortunately, we do not yet know which pathogen triggers this inflammation and which immune reaction of the body determines the course of the disease. It is remarkable that this disease only occurs in newborns. So we can only wait until clinical and basic research, in which our center plays a leading role, provides further insights. Only then will we be able to treat the cause of this disease and perhaps even prevent biliary atresia in the future.

A major challenge is the timely diagnosis of biliary atresia. Because among the almost 50% of newborns who develop harmless, transient jaundice during the first few days of life, the patients who are actually ill must be recognized as early as possible. For this reason, every newborn with jaundice lasting longer than 14 days should receive a more precise diagnosis. The first priority here is a precise examination of the "bilirubin" in the blood. Bilirubin is a yellow breakdown product of red blood cells and therefore a pigment of bile. Red blood cells live for around 120 days, after which they are broken down by the liver and spleen. After this, the so-called "indirect" bilirubin is produced, which is transported further in the body to the liver. There it is converted into so-called "direct" bilirubin, which is then excreted into the intestine via the bile. In biliary atresia, the direct bilirubin in the child's blood is therefore typically elevated. If bilirubin values are not within the normal range for the child's age, further examinations are required by an appropriately specialized paediatrician (paediatric gastroenterologist) and later at a paediatric liver center. The Pediatric Surgery Center at the MHH is one of these centers. Extensive examinations are then carried out here, including an examination of the bile ducts (endoscopic retrograde cholangiopancreatography or ERCP*). If the diagnosis of "biliary atresia" is confirmed, open surgery must be performed.

Since 2017, there has been an early detection program in Lower Saxony to detect patients with biliary atresia as quickly as possible. In addition to the yellow discoloration of the skin and sclerae mentioned above, the child's stool is discolored (whitish or grey). To make it easier to identify this color change, a stool color chart is included with every yellow screening booklet (created for every newborn). On it is a color scale with which the color of the stool in the diaper can be compared. This color comparison scale can also be used with an app that can be downloaded for Android as well as from the Apple Store under the title "Lebercheck bei Babys". In the event of a conspicuous color pattern, the pediatrician should be consulted immediately, who will then decide whether and if so which further diagnostic measures are necessary. This initiative was launched by the MHH together with the Techniker Krankenkasse and will be continued until further notice.

 

 

Until the 1950s, biliary atresia was considered incurable. In 1959, the Japanese pediatric surgeon Morio Kasai succeeded for the first time in developing a surgical technique to replace blocked bile ducts. In this way, the first patients survived the disease. Today, there are young women diagnosed with biliary atresia who have been cured by this operation and already have healthy children of their own. The surgical technique developed by Kasai has been technically refined over the years, but without abandoning the principle of the operation. The aim of the procedure is to remove the diseased and blocked bile ducts, which are located outside the liver. The hepatic portal** is then prepared in such a way that as many of the delicate bile ducts that leave the liver at this point as possible are cut and opened. These are so small and delicate that they can only be seen under a microscope. If these small bile ducts are not destroyed by the disease, there is a chance that the bile produced by the liver can be emptied into the intestine via them. In order to collect this "dripping" bile, an intestinal loop is used, which is sewn into the hepatic portal with its open end like a funnel and collects the bile. After 50 cm, this intestinal loop is connected to a second intestinal loop, which transports the digestive secretions and food further towards the large intestine.

It should be borne in mind that biliary atresia is an inflammatory process that is not influenced by the operation itself. It merely creates the conditions for a free outflow of bile when it resumes. This process can be supported by the administration of anti-inflammatory medication, which we will explain to you in detail before a planned operation.

All children are treated in our center according to the above-mentioned operation principle. After the Kasai operation, they require different lengths of follow-up treatment. The administration of antibiotics begins during the operation and continues later. These are intended to prevent infection of the bile ducts or liver. In addition, preparations are given to support the flow of bile (ursodeoxycholic acid) and missing nutrients (especially vitamins A, E, K and D) are replaced. In order for the children to thrive optimally, it is often necessary to enrich the diet with special fats (medium chain triglycerides or "MCT fats") due to the disruption of fat digestion. Some of these medications and diets can be discontinued later and are no longer necessary if the bile flow normalizes, the children develop well and gain weight continuously.

Prognosis
Over 90% of patients in whom biliary atresia is discovered early (within the first 60 days of life) and who are treated in a pediatric liver center survive for the next 10 years. Around half of them can continue to live for many years with their own liver, while the other patients require a liver transplant sooner or later. However, because biliary atresia is a disease that is not necessarily cured by the operation, the progressive connective tissue remodeling and hardening (fibrosis) of the liver can progress in patients. This process varies greatly from person to person and it is not possible to make a reliable prognosis, especially at the beginning of the disease.

On the other hand, we now know that children who have undergone Kasai surgery in good time have a realistic chance of surviving for a long time with their own liver. The only reliable prognostic marker is the bilirubin level. If this is within the normal range at the age of 6 months, then the chances are very high that the patient can lead an essentially unimpaired life with a very good long-term prognosis. This survival rate depends, among other things, on the experience of the respective center. Today, it can be assumed that in the few large children's centers with a focus on hepatology, a good 50% of children with biliary atresia have a good chance of continuing to live with their own liver in the medium and long term.