Biliary atresia is a congenital condition where a section of the bile ducts is either narrowed or absent. The bile ducts transport bile from the liver to the intestines. Bilirubin is conjugated by the liver and excreted in the bile. When the bile cannot be transported to the intestines for excretion in the stool, conjugated bilirubin builds up, causing jaundice.
Presentation
Biliary atresia presents with neonatal jaundice, with yellowing of the skin and sclera caused by raised conjugated bilirubin.
Obstructive jaundice (caused by obstruction to the excretion of bilirubin through the bile ducts) also causes:
- Pale stools (bile and bilirubin give stools their dark colour)
- Dark urine (as excess bilirubin is excreted in the urine)
Physiological jaundice is normal from 2 – 7 days of age. Physiological jaundice is caused by an increased breakdown and turnover of red blood cells, releasing unconjugated bilirubin. Additionally, their liver is less developed, with a slower clearance of bilirubin.
Features that separate jaundice caused by biliary atresia from physiological jaundice are:
- Biliary atresia causes persistent jaundice (more than 14 days in term babies and 21 days in premature babies)
- Biliary atresia causes raised conjugated bilirubin versus unconjugated bilirubin in physiological jaundice
Diagnosis
A blood test to measure the conjugated and unconjugated bilirubin is the initial investigation. Raised conjugated bilirubin suggests biliary atresia.
Ultrasound is the initial imaging.
Further specialist investigations, such as a HIDA scan, MRCP and liver biopsy, may be arranged.
Management
A Kasai portoenterostomy procedure involves removing the bile ducts and attaching a section of the small intestine to the liver where the bile duct was attached. Bile drains directly from the liver into the intestines through this attached section. This is somewhat successful and can clear the jaundice and prolong survival.
Often, a liver transplant is required.
Last updated February 2025
Now, head over to members.zerotofinals.com and test your knowledge of this content. Testing yourself helps identify what you missed and strengthens your understanding and retention.
How to Learn Medicine Course