Types Of Liver Transplantation In Children

Orthotopic liver transplantation 

When the liver is taken out of the patient and removed, a cadaver's or living donor's liver is transplanted in the same anatomical position. A new transplant is introduced in the same anatomical position after removing the original liver. It is considered to be the most common type of liver transplantation.

Auxiliary liver transplantation

The native liver is kept in situ, and an additional liver transplant is placed nearby. It is commonly done in Crigler-Najjar syndrome type 1 as well as some cases of acute hepatic failure. The western countries are moving more towards auxiliary liver transplantation as much as possible, except on certain occasions.

Indications for Liver Transplantation in Children

Obstructive biliary tract disease 

This is the most common indication as a group. It includes conditions like:

Biliary atresia 

It is also known as extrahepatic biliary atresia. It is the single most common indication for transplant. 50% of liver transplants are done for biliary atresia. These children may have biliary atresia; either the Kasai portoenterostomy has been done and a liver transplant is being performed, or they may be the ones in whom the Kasai surgery has not been done and they are directly being taken up for the surgery. Biliary atresia liver transplant is successful if performed within 1 year of age

Primary sclerosing cholangitis · Obstructive biliary tract disease secondary to either trauma or some procedure or surgery done on the liver.

Also read: Leukemias In Children

Metabolic disorders

It is the second most common as a group. It include: 

• Tyrosinemia type 1
• Glycogen Storage diseases type IV 
• Wilson's disease 
• Gestational Alloimmune Liver diseases or Neonatal Hemochromatosis
• Urea cycle defects 
• Organic acidemias

Acute hepatic failure 

It can be idiopathic acute hepatic failure or secondary to other conditions like drugs.

Chronic hepatitis with Cirrhosis 

It is seen in conditions like chronic hepatitis B virus infection and chronic hepatitis C virus infection, etc. 

Primary liver tumors 

Among primary liver tumors, the majority of the children are found to have hepatoblastoma. 

Hepatoblastoma is initially treated with chemotherapy, followed by total hepatectomy with liver transplant.

Miscellaneous causes 

• Alpha-1 antitrypsin deficiency 
• Alagille syndrome 
• Drug- or toxin-induced hepatotoxicity 
• Hemophilias A and B—particularly if they are complicated by transfusion-associated hepatitis.

Also read: Neonatal Cholestasis: Causes, Diagnosis, and Treatment in Infants

Scoring System used in Pediatric Liver Transplant

Multiple scoring systems have been devised for their use in predicting the prognosis. Earlier, there was a scoring system known as Child Turcott's Pugh scoring system, which was used in cirrhotic liver disease patients. But it was not found to be as reliable in children and was not found to be as good as the new score that was devised. Currently, the modification of the original MELD system is followed. The MELD score 

• A score known as the MELD score is used in adults who require liver transplants. 
• MELD stands for Model for End Stage Liver Disease. 
• It is a slightly complicated score that requires an algorithm where the investigation values are fed and then the score comes. However, it is a very sensitive and more reliable score for predicting outcomes of liver transplant. The MELD score basically incorporates 3 parameters:
  • Serum bilirubin 
  • Serum creatinine 
  • International Normalized Ratio (INR)

MELD = 3.78 x log serum bilirubin (mg/dL) + 11.20 x log e INR + 9.57 x log serum creatinine (mg/dL) + 6.43 (constant e for liver disease etiology). Higher scores indicate the more severe status of the patient. In children, the modification of the MELD score is followed by the PELD score. PELD score: It is useful in children <12 years of age. The components of the PELD score include: 

• Serum albumin 
• Total serum bilirubin 
• INR 
• Growth failure: A WHO-recommended chart is taken for determining whether the child is having any degree of growth failure or not. 
• Age <1 year. 

Also read: Gastrointestinal Foreign Bodies in Children: Bezoars &amp; Ingestion

Surgical Techniques

Whole liver transplant 

One liver is removed and another liver is put, which is from a cadaver or a recently diseased individual. It cannot be performed on a living patient. 

Split liver transplant 

It can be either Cadaver-based or living donor-based. In a living donor, usually the left liver segment, which is smaller in size and has a slightly different arterial supply, is taken away and it is transplanted into a young child. In the case of a cadaver, 2 segments can be used. The left part of the liver can be taken out for a child and the right part for an older patient or the older child.

Piggybank technique

In the Piggybank technique, the hepatic veins are anastomosed to the recipient IVC by an end-to-side anastomosis. The liver segment of the donor liver is taken, and the small segment of the inferior vana cava is also taken. This inferior vena cava is directly attached in an end-to-side anastomosis to the patient's inferior vena cava. It can be done at the level of the IVC or hepatic vein.

Also read: Autoimmune Hepatitis: Types, Clinical Presentation, Diagnosis

Contraindications for Liver Transplant 

1. Uncontrolled extra hepatic infections, including sepsis. 
2. Extra hepato biliary malignancies 
3. Uncorrectable severe congenital anomalies. 
4. Metastatic malignancy to the liver 
5. Cholangiocarcinoma 
6. Life-threatening severe dysfunction of other organ systems 
7. If the patient is having uncontrolled CCF, a liver transplant cannot be done. If the patient is having an uncontrolled acute kidney injury, then a hepatic transplant cannot be performed until the disease is under control.

Immunosuppressive Regime after Liver Transplant

Initial therapy 

The first-line drugs are a combination of prednisolone (corticosteroids) along with mycophenolate mofetil. If this regime fails, 2nd-line therapy is given. 

2nd line therapy 

Tacrolimus or calcineurin inhibitors with or without other drugs like azathioprine. 

Maintenance therapy 

It is later used for maintenance. Low-dose Tacrolimus can be used. Steroids are not used for maintenance.

Also read: Reye's Syndrome: Understanding A Rare But Serious Illness

FAQs About Pediatric Liver Transplants

Q. When was the first paediatric liver transplant performed, and by whom?

Ans. Dr. TE Starzl in 1963 

Q. When was the first successful paediatric liver transplant performed, and by whom? 

Ans. Dr. TE Starzl in 1967 

Q. When was the first successful liver transplant done in an Indian setting?

Ans. Dr. V. Poonacha and Dr. Anupam Sibal in 1998 

Q. What is the most reliable score for liver transplantation overall? 

Ans. MELD score 

Q. What are the 3 components of the MELD score? 

Ans. 

1. Serum bilirubin. 
2. Serum creatinine. 
3. International Normalized Ratio (INR). 

Q. What are the components of the PELD score? 

1. Serum albumin 
2. Total serum bilirubin 
3. INR 
4. Growth failure 
5. Age <1 year.

Q. What are the conditions where auxiliary transplantation is commonly done in children? 

Ans. Crigler-Najar syndrome type 1 and acute hepatic failure. 

Q. What is the most common malignancy where the liver transplant is performed in children? 

Ans. Hepatoblastoma. 

Also read: Mitochondrial Hepatopathies

Hope you found this blog helpful for your NEET SS Pediatrics Gastroenterology Preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.

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