Congenital hepatic fibrosis
Congenital hepatic fibrosis, or CHF is a rare disease that affects the liver. It is congenital, which means a person is born with it. Medical experts believe that it has a genetic cause, but they do not know which genes are involved. Congenital hepatic fibrosis does not usually appear on its own but is often part of a complex of other diseases, especially those that affect the kidneys. The condition, by itself or along with other syndromes, appears in about 1 in 10,000 to 1 in 20,000 live births.
Definition & Facts
Babies who are born with congenital hepatic fibrosis have abnormal bile ducts. The blood vessels that send blood to the liver from the patient’s gastrointestinal tract, or GI tract are also abnormal. The portal tracts, which carry bile, blood, and lymph in and out of the liver, accumulate scar tissue that prevents them from working properly.
The scarring and malformation in the portal tracts and the liver’s blood vessels cause a type of high blood pressure called portal hypertension. This high blood pressure interrupts the circulation of blood in the patient’s digestive system and puts pressure on the veins in digestive organs such as the esophagus, stomach, and intestines. The walls of the veins become thin and fragile and are at high risk of hemorrhaging.
Symptoms & Complaints
- Pain in the abdomen.
- Failure to thrive, which is seen more often in babies with an accompanying kidney disease.
- Vomiting blood.
- Blood in stool or black, tarry stools (melena).
As the disease progresses, the liver becomes harder, which makes the passage of blood through the organ more difficult. Blood eventually bypasses the liver and can cause swollen veins in the patient’s esophagus called esophageal varices. Varices can also appear in the stomach and the small intestines. If these varices start to bleed, it must be considered a medical emergency.
Experts believe that a number of genes cause congenital hepatic fibrosis. They believe that in most cases a person has to inherit a mutated gene from both parents to develop the disease and its comorbidities. This is called an autosomal recessive genetic disorder.
These genes control the development of the bile ducts and the portal veins, but mutations on the genes lead to the malformation of these structures as the embryo develops in the womb.
The problem probably begins very early in fetal development in a cylindrical collection of cells called ductal plates. Normally, these plates become bile ducts, but in congenital hepatic fibrosis they remain in an immature state. The portal vein is also malformed, and the portal tracts accumulate scar tissue.
Diagnosis & Tests
A doctor examines the child to determine if and how the liver and the spleen are enlarged and if they have any other liver disease. The doctor orders blood tests to evaluate how the liver and the kidneys are functioning as well as imaging tests such as computed tomography (CT) scans and ultrasounds of the spleen, kidney and liver.
A magnetic resonance cholangiopancreatography is another imaging test that allows the doctor to examine the bile and pancreatic ducts. This test is a type of magnetic resonance imaging (MRI) test given while the patient is under general anesthesia.
The liver may be biopsied to assess the extent of the scarring, and the child may be given an upper gastrointestinal endoscopy to look for esophageal varices. An endoscopy is the use of a long, flexible tube connected to a video monitor. This allows the gastroenterologist to see the inside of the patient’s GI tract. An endoscopic retrograde cholangiopancreatography is a test performed under general anesthesia which helps the doctor evaluate the bile ducts.
Treatment & Therapy
The treatment for congenital hepatic fibrosis depends on the extent of the symptoms. Some children are asymptomatic and do not need specific treatment, but they will need to be monitored. Regular physical examinations tell the doctor if the condition is getting worse, and blood tests tell them how well the liver is functioning.
Esophageal varices can be treated through banding, medication, sclerotherapy or shunt surgery. In banding, rubber bands are placed around the varices to shrink them. This treatment may need to be repeated. In sclerotherapy, the varices are injected with a solution that destroys them. The doctor gives the child medicines to lower the pressure in the liver’s blood vessels. Shunting is an operation that diverts blood from the esophageal varices. This is an uncommon operation and is done if banding does not work.
Medications which provide vasoconstriction such as vasopressin and somatostatin may be prescribed in order to reduce portal hypertension. In rare cases, liver transplantation may be recommended if all other therapies fail.
Prevention & Prophylaxis
Hypertension in the hepatic blood vessels that leads to the varices in the esophagus, stomach, and intestines needs to be watched. Congenital hepatic fibrosis patients have a slightly higher risk of contracting liver cancer, and they should be regularly monitored for this disease as well.