Pediatric Liver Transplant

Liver transplantation is an established treatment for children with end-stage liver disease and offers the opportunity for a long and healthy life . In previous decades, it has become a state-of-the-art operation with excellent success and limited mortality . Graft and patient survival have continued to improve as a result of improvements in medical, surgical and anesthetic management, organ availability, and immunosuppression.

Organ scarcity, which is the main limitation to the full exploitation of transplantation, is being overcome, thanks to the technique of split-liver and living-donor transplantation which have contributed to reversing a situation in which, during the 1980s and 90s, children had greater waiting list mortality compared to that of adult patients.

Several years ago, the main focus of care of children with end-stage liver disease was to find a liver transplant, but today, the main interest is in long-term follow-up, with prevention of immunosuppression-related complications and promotion of as normal growth as possible.

Pretransplant care:

Pediatric patients with end stage liver disease are a sick group with compromised immunity and most are nutritionally depleted. A slightest of stress may tip the balance and lead to decompensation. Therefore they need to be optimised prior to transplant.

Active infection is a contraindication for transplantation and needs adequate treatment.

Nutritional support to optimize growth.

Any sign of GI bleed requires endoscopy with variceal banding Prevention or treatment of drug-induced side effects (e.g. osteopenia secondary to prolonged steroid intake).

Assess the immunological status of the child; immunizations when possible prior to transplant as per age.

Indications:

The main indications for liver transplantation in the pediatric population are:

Extra-hepatic cholestasis: biliary atresia. Intra-hepatic cholestasis: sclerosing cholangitis, Alagille’s syndrome, non-syndromic paucity of intrahepatic bile ducts, and progressive familial intrahepatic cholestasis. Metabolic diseases: Wilson's disease, α1-antitrypsin deficiency, inborn errors of bile acid metabolism, tyrosinemia, disorders of the urea cycle, oxaluria type I and disorders of carbohydrate metabolism. Acute liver failure. Others: primary liver tumor and cystic fibrosis.

In young children, the most common liver disease leading to transplantation is biliary atresia. Biliary atresia accounts for at least 50 percent of all liver transplants in children

Contraindications to Liver Transplantation:

Current contraindications to liver transplantation in children are:

Non-resectable extrahepatic malignant tumor. concomitant end-stage organ failure that cannot be corrected by a combined transplant. uncontrolled sepsis and irreversible serious neurological damage. Whereas in adults there are limitations to access to liver transplantation waiting lists for patients with primary liver tumors, in children, the approach is much more liberal and the indication should be discussed on a case by case analysis with pediatric oncologists.

Evaluation of the Transplant Candidate:

The primary goal of the evaluation process is to identify appropriate candidates for liver transplantation and to establish a pre-transplantation plan The following steps are usually considered:

Confirm the indication for transplantation. Determine the severity of the disease. Consider alternative treatments to transplantation. Exclude contraindications to transplantation. Identify active infections and assess the immunological status of the child. Rule out cardiac malformations that might need to be corrected before transplantation. Establish a pre-transplant therapeutic plan: immunizations, when possible, nutritional support to optimize growth, dental care. Inform parents, and the patient if possible, on the transplantation procedure and on the post-transplantation period in order to motivate and prepare them to accept and deal with all issues and possible complications of the procedure and Evaluate social status and logistic issues.

Waiting period:

Earlier the mortality risk on the waitlist was quite high in pediatric population as compared to adults because of the scarcity of organs. Thanks to the newer technique of split liver transplant ( in which the deceased liver is split into two) and living related liver transplant which have reversed the scenario and led to an increase in donor pool and decreased the waiting period.

LTP technique:

The first liver transplant was performed by Thomas Starzl, in 1963, on a 2-year-old child affected by biliary atresia. The patient died in the operating room of uncontrolled hemorrhage. After this first case, and up to the early 1980s, the only technical option for pediatric liver transplantation was to transplant the whole liver of a donor with a weight as close as possible to that of the recipient. The technique involved explantation of patients diseased liver followed by implantation of donor liver. Given the low number of pediatric donors, up to 50% of the children on the waiting list would die before they could receive a transplant. The development of techniques that allowed surgeons to transplant portions of livers from adult donors has completely changed the fate of liver transplantation in pediatric patients.

Whole-liver transplantation:

The procedure of whole-liver procurement in pediatric donors can be performed exactly as in adults. Problem with this technique is the availibilty of the size match of the donor liver with that of patients body.

Reduced-size liver transplantation:

This procedure consists of procurement of the whole liver from an adult cadaver donor, which is reduced in its size on the back-table. This technique of parenchymal reduction, very seldom used today, allows surgeons to overcome differences in size between the donor and the recipient of up to four or five times.

Split-liver transplantation:

After procuring whole liver from a cadaver donor and dividing it into two sections, leaving the vascular structures for the two portions of hepatic parenchyma intact. In this way, two partial organs are obtained from a single liver: the left lateral segment (segments 2 and 3), which can be transplanted in a child, and the extended right liver (segments 1 and 4-8), which can be transplanted into an adult.

Living-related liver transplantation:

The first description of the procedure in which a segment of liver was procured from a living donor (the mother), and transplanted in a child affected by biliary duct atresia, dates back to 1988. Living-related liver transplants soon came to account for a substantial number of pediatric cases performed in many centers throughout the world. The type of graft i.e. the segment of liver depends on body weight of the patient.

Patients with a body weight less than 10 kgs require a left lateral segment. Patients with a body weight between 10-30 kgs require a left lobe graft. Patients with a body weight more than 30 kgs require a right lobe graft.

Postoperative care:

Post transplantation these patients are managed in dedicated transplant ICUs. Postoperative care involves a joint effort of pediatric transplant hepatologist, transplant surgeon, well trained nurses, radiologist, dietician and physiotherapist. The early postoperative period consists of managing problems related to technical complications and to the prevention, diagnosis, and treatment of acute rejection and infection episodes. Antibiotic and antifungal prophylaxis is given in the first week depending on the departmental policy . USG doppler is done daily twice a day during first week to look for graft inflow and outflow. Antiplatelet prophylaxis is given to prevent thrombotic vascular complications.

To ward of rejection these patients require immunosuppression starting in the immediate postoperative period which requires strict adherence and compliance for whole life with regular monitoring of blood levels.