Biliary Atresia

INTRODUCTION

Biliary atresia is a disorder of the liver that may be present at birth or develop shortly after. It is characterized by the absence or obstruction of the bile drainage system within the liver.

The biliary system consists of small tubular channels called bile ducts. These ducts transport bile from the liver to the gallbladder for storage and then to the small intestine to aid digestion. Bile, produced by liver cells, contains cholesterol, bile salts, and waste materials such as bilirubin. Its main functions are the removal of toxins from the body and assisting in fat digestion along with absorption of fat-soluble vitamins (A, D, E, and K).

MEANING

Atresia: Refers to the congenital absence or closure of a normal body opening or tubular structure.

Biliary atresia: A condition in which one or more bile ducts are either absent or severely narrowed at birth, leading to persistent jaundice and progressive liver damage.

It occurs due to improper development of bile drainage pathways in the fetus (baby growing in the womb). This results in inflammation and blockage of bile ducts soon after birth. Consequently, bile accumulates in the liver, damaging liver cells and eventually leading to scarring and cirrhosis.

INCIDENCE

• Occurs in approximately 1 in 10,000 live births.
• More frequently seen in Asian populations (about 1 in 5,000).
• Slightly more common in females than males.

TYPES

The two types of biliary atresia are fetal and perinatal

• 1. Fetal biliary atresia
  • Develops when the baby is in mother’s womb.
  • Often associated with other birth defects (of other organs like heart, spleen, intestine).
• 2. Perinatal biliary atresia
  • It occurs immediately after birth and is more common type.
  • Postnatal inflammatory injuries appear to lead to worsening of an already developmentally susceptible newborn.
  • Symptoms appear between 2–4 weeks after birth.
• Around 90% of cases occur as isolated conditions.
• About 10% are associated with other congenital abnormalities.

CAUSES

• The cause of biliary atresia is not known
• The perinatal type is often associated with a later onset of jaundice and may be caused by environmental factors.
• Biliary atresia is not a hereditary condition, which means it is not transmitted from parents to their offspring. As a result, individuals who have had biliary atresia do not carry an increased risk of passing this condition on to their children.
• Biliary atresia is most likely caused by an event in the womb or around the time of birth. Possible triggers of the event may include one or more of the following:
  • A viral or bacterial infection after birth
  • An immune system problem, such as when the immune attacks the liver or bile ducts for unknown reasons
  • A genetic mutation, which is a permanent change in a gene’s structure
  • A problem during liver and bile duct development in the womb
  • Exposure to toxic substances

IMPACT OF BILIARY ATRESIA ON THE BABY

The bile ducts that transport bile from the liver to the gut are gradually destroyed by biliary atresia, which starts outside the liver and eventually affects the bile ducts inside the liver.

Bile trapped inside the liver produces damage and scarring that can end in cirrhosis, which makes it difficult for the liver to eliminate toxins from the blood, because the damaged ducts prohibit bile from draining from the liver.

The liver gradually deteriorates and malfunctions as a result of these poisons accumulating in the blood.

The liver grinds up on the vein walls, leaving scars. The veins get constricted as a result, making it difficult for blood to flow through them.

This results in elevated blood pressure in the liver's blood arteries.

If therapy is not received, the baby's liver will eventually fail and require a liver transplant.

WHEN DOES IT APPEAR?

Babies are usually normal at birth. Symptoms start appearing within the first 2–8 weeks of life.

SIGNS AND SYMPTOMS

Biliary atresia symptoms typically start to show about two to eight weeks after birth and include:

• Jaundice that does not go away in a week or two (jaundice happens when the liver does not eliminate bilirubin)
• Excessive bilirubin in the bloodstream that travels to the kidneys is the cause of dark yellow or brown urine.
• Pale or clay-colored stools
• An enlarged liver or abdomen
• Inadequate weight gain and feeding issues

DIAGNOSTIC EVALUATION

Biliary atresia cannot be definitively diagnosed by a single test; therefore, multiple tests are required. It is important to examine for liver damage in all newborns who still have jaundice two to three weeks after delivery or who have grey or white stools after that time.

A pediatric gastroenterologist, hepatologist, or surgeon is typically consulted for infants with suspected liver injury.

Blood test: elevated bilirubin levels may be a sign of bile duct obstruction

Abdominal X-rays: Sedation may be given to keep babies calm, but anesthesia is not required. X-rays of the abdomen are used to look for enlarged spleen and liver.

Ultrasound: Sedation may be given to keep the baby still, but anesthesia is not required. The pictures can reveal whether the bile ducts or liver are enlarged, as well as whether tumors or cysts are obstructing the bile flow.

Liver scan: This type of x-ray uses chemicals to produce an image of the bile ducts and liver. A nuclear medicine technician often performs a liver scan at a hospital or outpatient facility..The infant will usually receive general anesthesia or be sedated before the procedure. The liver scan, uses injected radioactive dye to trace the path of bile in the body. The tests can show if and when bile flow is blocked. Blockage is likely to be caused by biliary atresia.

Liver biopsy: Using ultrasound imaging to guide the biopsy needle into the liver, the procedure is carried out under mild sedation and local anesthesia. The likelihood of biliary atresia can be determined via a liver biopsy.

Diagnostic surgery: In order to directly inspect the liver and bile ducts, a pediatric surgeon creates an abdominal incision. A Kesai operation is typically carried out right away if the physician determines that biliary atresia is the issue. The Kasai operation and diagnostic surgery are carried out in a hospital. During the procedure, the baby will be under general anesthesia.

MANAGEMENT

The primary treatment for biliary atresia is surgical intervention known as the Kasai procedure. If this procedure is unsuccessful, the child eventually requires a liver transplant

KASAI PROCEDURE

The Kasai procedure, developed by the surgeon who first described it, is the standard initial treatment for biliary atresia.

In this surgery, the damaged bile ducts are removed, and a segment of the intestine is connected directly to the liver to enable bile drainage into the small intestine.

Although it does not completely cure the condition, it helps improve bile flow and reduces complications associated with bile accumulation.

Without surgical treatment, survival beyond two years of age is rare.

The surgery is ideally performed before 60 days of life to achieve better outcomes.

It is most beneficial when done early, particularly before permanent liver damage has developed.

Some infants respond well to the procedure and may remain symptom-free, with resolution of jaundice and improved liver function.

MEDICINES

Medications are provided to:

• Support liver function
• Maintain adequate nutrition

LIVER TRANSPLANTATION

• A liver transplant may be necessary if liver damage continues to worsen.
• If the Kasai procedure does not work, most infants require transplantation within the first 1–2 years of life.
• Even after a successful Kasai procedure, progressive liver scarring (cirrhosis) may occur over time, making transplantation necessary later in life.

WHY EARLY DETECTION MATTERS?

• Early diagnosis and treatment enhance bile drainage, delay liver damage, and improve survival rates.
• Delayed intervention increases the risk of cirrhosis and eventual liver failure.

KEY MESSAGE FOR PARENTS AND CAREGIVERS

If a baby has persistent jaundice beyond 2 weeks, pale stools, or dark urine, seek medical care immediately. Early action can save the child’s liver and life.

Disclaimer:

This information is provided for educational purposes only. Besides sources from ILBS, some of the content is derived from data found at:

• Healthdocbox.com
• Chp.edu
• Pdffox.com
• Liverfoundation.org
• Search.fasthealth.com
• Findresearcher.sdu.dk