Atresia of Intrahepatic Bile Ducts - Causes, Symptoms, Diagnosis, and Treatment

Creator: Dr. Namrata Singhal
Published: 2023-04-13T16:05:54

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Atresia of intrahepatic bile ducts is defined as the partial or complete absence or destruction of all or part of a bile duct that is present inside your liver.

Written by

Dr. Namrata Singhal

Medically reviewed by

Dr. Ghulam Fareed

April 13, 2023

April 18, 2023

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Contents

What Is Atresia of Intrahepatic Bile Ducts?
What Is the Cause of Atresia of Intrahepatic Bile Ducts?
What Are the Clinical Features Based on the Classification of Atresia of Bile Ducts?
How Is the Screening of Atresia of the Intrahepatic Bile Duct Done?
What Is the Treatment of Atresia of Intrahepatic Bile Duct?

What Is Atresia of Intrahepatic Bile Ducts?

Intrahepatic biliary atresia is a congenital malformation of the whole or part of the biliary duct that is present in the liver or sometimes even congenital absence of it. It can commonly occur due to cytomegalovirus, cell-mediated inflammation, and also due to damage to the bile duct, which is autoimmune-mediated. There is also a possible role of the genetic mutation CFC1 gene in the etiology of the disease.

The condition may even lead to liver cirrhosis and liver failure if left untreated. It is an inflammatory disease involving any part of the bile tract causing the removal of bile in the liver through the intrahepatic bile duct. The incidence of this disorder is high in the Asian and Pacific regions. Females are more commonly affected by the disease than males. It is also known as newborn jaundice biliary atresia.

What Is the Cause of Atresia of Intrahepatic Bile Ducts?

The etiology of atresia in the intrahepatic bile duct is not known completely. Still, numerous factors contribute to the development of this disorder, including autoimmune-mediated reactions, cytomegalovirus infections, toxic, and even genetic factors.

What Are the Clinical Features Based on the Classification of Atresia of Bile Ducts?

Classification of Atresia of Bile Ducts:

1. Based on the Area Affected:

It can be classified into different types, such as:

Type 1- The common bile duct is affected in this case.

Type 2- It Is of two types:

Type 2a- In this type, the common hepatic duct is affected.
Type 2b- The common hepatic duct, cystic, and bile duct are affected in this type.

Type 3- In this type, the entire biliary tract is involved, including the intrahepatic duct, common hepatic duct, cystic duct, and common bile duct.

2. Based on the Time of Onset of Disease:

Early Onset Biliary Atresia- If symptoms appear within the first two weeks of birth, it is called early-onset biliary atresia.
Late Onset Biliary Atresia- If symptoms appear after two weeks of birth, it is called late-onset biliary atresia.

3. Based on the Organs Involved:

Syndromic Biliary Atresia- In this type, various congenital abnormalities such as asplenia (absence of spleen), polysplenia (presence of multiple spleens), cardiac or other intra-abdominal defects such as situs inversus (a disorder in which the internal organs are abnormally present on the opposite side of the body), preduodenal portal vein and the absence of retro hepatic inferior vena cava are found to be associated with the disorder.
Non-Syndromic Biliary Atresia- It accounts for approximately 90 percent of the cases. The patients usually complain of yellowish discoloration of the skin, sclera, and urine (jaundice) within the second or third week of the child’s birth. Alcoholic stools are seen resulting from less bile in the gastrointestinal tract due to bile duct obstruction and inflammation. Abdominal distension and hepatic (liver) enlargement may also be seen in infants. Additional symptoms may be developed by the patient, which include impaired weight gain, mood swings, and high blood pressure within the portal veins by the age of eight to ten weeks.

How Is the Screening of Atresia of the Intrahepatic Bile Duct Done?

Every patient with persistent jaundice for more than two weeks should be screened for intrahepatic biliary atresia.

Ultrasound- This should be carried out after twelve hours of fasting to check for the gallbladder. If the gallbladder is shrunk despite fasting, biliary atresia can be suspected.
Cholangiography- This test is carried out when ultrasound is clear to identify the morphology and patency of the biliary tract.
Liver Biopsy- A biopsy of the liver is usually carried out to exhibit the histological changes that might occur due to biliary atresia, which include bile plugs, the proliferation of the duct, swelling of the portal vein, and also liver fibrosis.
Antigen Testing for Cytomegalovirus- The disease can also be caused by the cytomegalovirus, which can be identified through antigen testing for cytomegaloviruses such as IgM and IgG.
Biochemical Liver Function Tests- These testsinclude abnormal liver function tests that are seen in almost all cases of intrahepatic bile duct atresia. Serum bilirubin and other liver function tests are elevated. The serum protein is also found to be decreased. These liver function tests exhibit the extent of parenchymal damage to the liver.
Stool Color Cards- Stool color is screened in infants for biliary atresia. The color of the stool is monitored for approximately one month by the patient and then compared with the color cards for diagnosis. However, the specificity of this test is low.

The stool color and the conditions assessed are the following.

Red- Lower gut or rectum is bleeding.
White, Clay-Colored- Antidiarrheal, lack of bile juice.
Green- Antibiotics, a bacterial infection.
Yellow- Excess fat, infection of the small intestine.
Black or Dark Brown- Iron supplements, bleeding in the upper gastrointestinal tract.

What Is the Treatment of Atresia of Intrahepatic Bile Duct?

Some common medicines are given to patients suffering from this disorder which include multivitamins. Fat-soluble vitamins are administered since there is a deficiency of this fat-soluble vitamin due to the absence of bile juice. Lactulose and antiviral therapy are other medications given to the affected patient. Liver transplantation is the most common indication for the treatment of biliary atresia in newborns.

It can be treated with a surgical intervention called a Kasai procedure if it is diagnosed early. If diagnosed within the first two months of birth, the Kasai procedure can be performed. In this procedure, the portion of the necrosed bile duct is surgically removed, and the healthy duct is joined with the intestine for bile flow. Still, the success of this technique depends upon the quick diagnosis of the disease. This procedure has certain complications, including infection and failure of this procedure.

For the treatment of intrahepatic biliary atresia, a liver transplant is suggested. The liver is obtained from any cadaveric donor( a donor who is of the same age only a few lobes of the liver are taken for this procedure) or from a living parent donor. The prognosis has improved for liver transplant patients. The mortality rate has decreased in recent times in these patients due to the advent of new techniques such as liver graft splitting and living-related donors.

Conclusion

Atresia of intrahepatic bile ducts is a condition characterized by the partial or complete absence or damage of all or portion of a bile duct that is present inside the liver. Early diagnosis of the condition is essential to treat the infant with surgical procedures. Liver transplantation is crucial in advanced cases. Once the liver is transplanted, parental feeding for two days is recommended for the patient for quick recovery.

Frequently Asked Questions

1. What Are the Procedural Steps Involved in Conducting an Open Exploration of the Common Bile Duct?

The procedural steps involved in conducting an open exploration of the common bile duct typically begin with the patient's anesthesia and positioning on the operating table. A surgical incision is made in the abdomen, allowing the surgeon access to the abdominal cavity. The common bile duct is identified and carefully dissected to expose it. Depending on the purpose of the exploration, various techniques, such as cholangiography or choledochoscopy, may be employed to visualize and assess the duct's condition. Any necessary interventions, such as stone removal or stent placement, are performed, and the incision is closed meticulously. This procedure is carried out precisely to diagnose and address issues within the common bile duct, ensuring optimal patient outcomes.

2. How Is Removal of a Stent from the Common Bile Duct Typically Performed?

The removal of a stent from the common bile duct is typically performed using endoscopic techniques. In this procedure, known as endoscopic retrograde cholangiopancreatography (ERCP), a flexible endoscope is inserted through the patient's mouth and advanced through the digestive tract until it reaches the common bile duct. Once the stent is visualized, specialized tools are used to grasp and carefully remove it. ERCP allows for precise and minimally invasive stent removal, reducing the need for surgical intervention. It is an established method for managing stents placed in the common bile duct and is generally well-tolerated by patients.

3. What Are the Potential Hazards Associated with the Exploration of the Common Bile Duct?

Exploring the common bile duct carries potential hazards that healthcare providers must be mindful of. This procedure carries certain risks, such as bleeding, infection, damage to surrounding structures like blood vessels or the duodenum, and bile leakage. There's also a chance of issues with anesthesia and the healing process after surgery. To mitigate these hazards, meticulous surgical techniques, careful patient monitoring, and adherence to infection control protocols are essential.

4. What Type of Drainage Method Is Employed in Common Bile Duct Exploration?

Common bile duct exploration employs a drainage method known as choledochostomy or T-tube placement. During this procedure, a T-shaped tube is inserted into the common bile duct and sutured to the abdominal wall. This allows for continuous bile drainage into a collection bag outside the body. T-tube drainage is utilized when there is a need to relieve obstruction, manage bile leakage, or conduct post-operative monitoring of bile flow. It provides a controlled means of diverting bile and allows for evaluation of ductal patency and healing. The tube is typically removed once the underlying condition is resolved or stabilized.

5. How Does an Obstructed Bile Duct Impact the Functioning of the Liver?

The liver's ability to function can be greatly impacted by an obstruction in the bile duct. The liver produces bile, which is essential for digestion and the removal of waste from the body. When a bile duct is obstructed, bile cannot flow properly into the digestive system, leading to a buildup of bile in the liver. This can result in liver damage, jaundice (yellowing of the skin and eyes), itching, and digestive issues. The liver's ability to process and detoxify substances may also be compromised. Timely intervention and treatment to relieve the obstruction are essential to prevent further liver damage and associated health complications.

6. What Distinguishes Intrahepatic Obstruction from Extrahepatic Obstruction?

Intrahepatic and extrahepatic obstructions are two distinct locations of bile duct obstruction within the liver. Intrahepatic obstruction occurs when the blockage is within the liver tissue, typically affecting smaller bile ducts inside the liver. On the other hand, extrahepatic obstruction occurs when the blockage is located outside the liver, usually in the common bile duct or the ducts leading to it. These two types of obstructions can have different causes, presentations, and treatment approaches. Distinguishing between them is crucial for accurately diagnosing and appropriately managing bile duct obstructions.

7. What Specific Changes Are Observed in Cases of Intrahepatic Biliary Atresia?

In cases of intrahepatic biliary atresia, specific changes are observed primarily within the liver and its bile ducts. The condition is characterized by the absence or underdevelopment of the intrahepatic bile ducts responsible for transporting bile from the liver to the common bile duct. This absence or malformation leads to bile accumulation within the liver, causing inflammation, fibrosis, and liver damage. Clinically, patients with intrahepatic biliary atresia often present with jaundice, pale stools, and hepatomegaly (enlarged liver). Timely diagnosis and intervention, such as the Kasai procedure or liver transplantation, are essential to address these changes and improve long-term outcomes for affected individuals.

8. What Treatment Approaches Are Utilized for Managing Intrahepatic Biliary Atresia?

The treatment approaches for managing intrahepatic biliary atresia typically involve surgical interventions. In order to restore bile flow from the liver to the intestine, the Kasai portoenterostomy is the main procedure used. In order to facilitate proper bile drainage, the damaged bile ducts within the liver are removed during the Kasai procedure, and a section of the intestine is connected directly to the liver. However, if the Kasai procedure is unsuccessful or liver damage has progressed significantly, a liver transplantation may become necessary. Timely diagnosis and prompt intervention are crucial for better outcomes in managing intrahepatic biliary atresia, as the condition can lead to severe liver damage if left untreated.

9. Could You Explain the Concept of the Intrahepatic Biliary System?

The intrahepatic biliary system, or intrahepatic bile ducts or intrahepatic biliary tree, is a network of tiny ducts and channels within the liver tissue. Its main job is to move bile, which is the liver's digestive fluid, through the bigger bile ducts and eventually the common bile duct, where it enters the small intestine to help with digestion. The intrahepatic biliary system plays a vital role in maintaining the balance of bile in the liver and facilitating the removal of waste products from the body. It is a critical component of the overall biliary system, essential for proper digestion and liver function.

10. What Is Considered the Normal Measurement for the Extrahepatic Biliary Duct?

The normal measurement for the extrahepatic biliary duct, which includes the common bile duct and the hepatic ducts, can vary slightly among individuals but typically falls within a range of approximately 6 to 8 millimeters in diameter when measured by medical imaging or endoscopic methods. Monitoring the size of the extrahepatic biliary duct is important in clinical practice, as significant dilatation or narrowing can indicate various underlying conditions or obstructions affecting bile flow.

11. What Is the Pathophysiology of Biliary Atresia?

The pathophysiology of biliary atresia involves the progressive inflammation and fibrosis (scarring) of the bile ducts both inside and outside the liver. This leads to the obstruction of bile flow from the liver to the intestine. While the exact cause remains unclear, it is believed to involve autoimmune factors and genetic predispositions. The blockage of bile flow causes bile to accumulate in the liver, leading to liver damage, jaundice, and other symptoms. If left untreated, biliary atresia can result in cirrhosis and severe liver dysfunction, making early diagnosis and intervention critical for better outcomes.

12. What Is Regarded as the Gold Standard Method for Diagnosing Biliary Atresia?

The gold standard method for diagnosing biliary atresia is a surgical procedure called intraoperative cholangiography. During this procedure, a contrast dye is injected into the bile ducts within the liver, and X-ray images are taken to visualize the bile duct anatomy. This allows for the direct assessment of the bile ducts' structure and any potential obstructions. Intraoperative cholangiography is considered the most reliable diagnostic tool for confirming biliary atresia because it provides a direct view of the condition of the bile ducts, allowing for accurate diagnosis and guiding the subsequent surgical treatment, such as the Kasai procedure or liver transplantation if necessary.

13. Which Diagnostic Test Is Considered the Most Reliable for Confirming Biliary Atresia?

As mentioned earlier, the diagnostic test considered the most reliable for confirming biliary atresia is the intraoperative cholangiography. This surgical procedure offers a direct and detailed view of the bile ducts within the liver, allowing for the assessment of their structure and any obstructions. However, additional diagnostic tests, such as liver biopsy and non-invasive imaging techniques like ultrasound and magnetic resonance cholangiopancreatography (MRCP), may also support the diagnosis and evaluate the extent of liver damage caused by biliary atresia. Combining these diagnostic approaches helps healthcare providers make an accurate assessment and determine the most appropriate treatment plan for affected infants.

14. How Is the Diagnosis of Biliary Atresia Typically Confirmed?

The diagnosis of biliary atresia is typically confirmed through clinical evaluation, imaging studies, and diagnostic procedures. While intraoperative cholangiography is considered the gold standard for confirmation, it is often preceded by non-invasive tests such as ultrasound, which can reveal signs of bile duct abnormalities and liver damage. Blood tests, including liver function and bilirubin levels, may also provide valuable diagnostic information. Ultimately, a conclusive diagnosis of biliary atresia is crucial for timely intervention and treatment planning to improve the prognosis for affected infants.

15. What Is the Most Prevalent Type of Biliary Atresia?

The most prevalent type of biliary atresia is "isolated biliary atresia." This form accounts for the majority of cases and is characterized by the obstruction or absence of the bile ducts both inside and outside the liver. In isolated biliary atresia, the condition primarily affects the bile ducts, resulting in the accumulation of bile in the liver, jaundice, and liver damage. Other forms of biliary atresia, such as syndromic or associated types, may involve additional congenital abnormalities or conditions beyond the bile ducts. Isolated biliary atresia is the most commonly encountered and studied subtype, and it typically requires surgical intervention for management.

Sources

Dr. Ghulam Fareed

Medical Gastroenterology

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