Auxiliary liver transplantation in children. Curr Opin Organ Transplant. 2011;16:489-493. [PMID: 21897245 DOI: 10.1097/mot.0b013e32834a94cf]

Pediatric Liver Transplantation: Selection Criteria and Post-transplant Medical Management

Pediatric liver transplantation remains the gold standard for life-threatening acute and chronic liver diseases and multiple liver-based inherited metabolic defects. Advances in surgical techniques, better perioperative care and immunosuppression regimes have resulted in excellent long-term graft and patient survival. The success of pediatric liver transplantation does however bring the additional challenge of long-term patient outcomes including graft hepatitis-related fibrosis and suboptimal biopsychosocial outcomes. In this review, authors will explore the current landscape of pediatric liver transplantation including indications, timing of referral for liver transplantation, surgical techniques and long-term outcomes such as recurrence of pre-transplant liver disease, idiopathic graft hepatitis and biopsychosocial outcomes. Ultimately, early identification and management of potential issues long-term helps ensure our recipients achieve a "meaningful survival".

Over 30 Years of Pediatric Liver Transplantation at the Charité-Universitätsmedizin Berlin

Background: Pediatric liver transplantation (LT) is the treatment of choice for children with end-stage liver disease and in certain cases of hepatic malignancies. Due to low case numbers, a technically demanding procedure, the need for highly specialized perioperative intensive care, and immunological, as well as infectious, challenges, the highest level of interdisciplinary cooperation is required. The aim of our study was to analyze short- and long-term outcomes of pediatric LT in our center. Methods: We conducted a retrospective single-center analysis of all liver transplantations in pediatric patients (≤16 years) performed at the Department of Surgery, Charité – Universitätsmedizin Berlin between 1991 and 2021. Three historic cohorts (1991–2004, 2005–2014 and 2015–2021) were defined. Graft- and patient survival, as well as perioperative parameters were analyzed. The study was approved by the institutional ethics board. Results: Over the course of the 30-year study period, 212 pediatric LTs were performed at our center. The median patient age was 2 years (IQR 11 years). Gender was equally distributed (52% female patients). The main indications for liver transplantation were biliary atresia (34%), acute hepatic necrosis (27%) and metabolic diseases (13%). The rate of living donor LT was 25%. The median cold ischemia time for donation after brain death (DBD) LT was 9 h and 33 min (IQR 3 h and 46 min). The overall donor age was 15 years for DBD donors and 32 years for living donors. Overall, respective 1, 5, 10 and 30-year patient and graft survivals were 86%, 82%, 78% and 65%, and 78%, 74%, 69% and 55%. One-year patient survival was 85%, 84% and 93% in the first, second and third cohort, respectively (p = 0.14). The overall re-transplantation rate was 12% (n = 26), with 5 patients (2%) requiring re-transplantation within the first 30 days. Conclusion: The excellent long-term survival over 30 years showcases the effectiveness of liver transplantation in pediatric patients. Despite a decrease in DBD organ donation, patient survival improved, attributed, besides refinements in surgical technique, mainly to improved interdisciplinary collaboration and management of perioperative complications.

Liver transplantation for pediatric inherited metabolic liver diseases

Liver transplantation (LT) remains the gold standard treatment for end stage liver disease in the pediatric population. For liver based metabolic disorders (LBMDs), the decision for LT is predicated on a different set of paradigms. With improved outcomes post-transplantation, LT is no longer merely life saving, but has the potential to also significantly improve quality of life. This review summarizes the clinical presentation, medical treatment and indications for LT for some of the common LBMDs. We also provide a practical update on the dilemmas and controversies surrounding the indications for transplantation, surgical considerations and prognosis and long terms outcomes for pediatric LT in LBMDs. Important progress has been made in understanding these diseases in recent years and with that we outline some of the new therapies that have emerged.

Liver transplantation for neonatal-onset citrullinemia

Citrullinemia or ASS deficiency in its classical form presents in the neonatal period with poor feeding, hyperammonemia, encephalopathy, seizures, and if untreated can be fatal. Despite advances in medical therapy, neurocognitive outcomes remain suboptimal. LT has emerged as a potential management option. A retrospective single-center review identified 7 children with a median age of 1.1 years (range, 0.6-5.8) at referral. Five children presented clinically, and 2 were treated prospectively from birth due to positive family history. All patients received standard medical and dietary therapy prior to LT. The indications for LT were frequent metabolic decompensations in 4, elective in 2, and ALF in 1. The median age at LT was 2.4 years (range, 1.3-6.5). Five patients received 6 left lateral segment grafts, one a live unrelated donor left lateral segment as an APOLT graft, and one a cadaveric whole liver graft as APOLT. One child required retransplantation due to hepatic artery thrombosis. Graft and patient survival were 86% and 100%, respectively. Median follow-up is 3.1 years (range, 0.1-4.1), and the median age at follow-up is 5.5 years (range, 4.0-9.8). There have been no metabolic decompensations in 6 children, while 1 patient (with APOLT) developed asymptomatic hyperammonemia with no clinical or histological signs of liver injury, requiring additional medical therapy. Our medium-term experience following LT in citrullinemia is favorable, demonstrating a positive transformation of the clinical phenotype.

Liver transplantation in children: state of the art and future perspectives

In this review, we provide a state of the art of liver transplantation in children, as the procedure is now carried out for more than 30 years and most of our paediatric colleagues are managing these patients jointly with liver transplant centres. Our goal for this article is to enhance the understanding of the liver transplant process that a child and his family goes through while explaining the surgical advances and the associated complications that could happen in the immediate or long-term follow-up. We have deliberately introduced the theme that 'liver transplant is a disease' and 'not a cure', to emphasise the need for adherence with immunosuppression, a healthy lifestyle and lifelong medical follow-up.

Current status of auxiliary partial orthotopic liver transplantation for acute liver failure

Auxiliary partial orthotopic liver transplantation (APOLT) is a technique of liver transplantation (LT) where a partial liver graft is implanted in an orthotopic position after leaving behind a part of the native liver. APOLT was previously considered technically challenging with results inferior to orthotopic liver transplantation. Results of this procedure have continued to improve with improving surgical techniques and a better understanding of the natural history of acute liver failure (ALF) and liver regeneration. The procedure is being increasingly accepted as a valid treatment option for ALF-especially in children. This article reviews the historical background to this operation, advances in the technique, and its current place in the management of ALF. Liver Transplantation 22 1265-1274 2016 AASLD.

Pediatric liver transplantation: Personal perspectives on historical achievements and future challenges

This review presents the author's personal perspective and contributions to the first steps, the development, the current status, and the remaining issues of pediatric liver transplantation (LT). Innumerable children around the world who have undergone LT have reached adulthood. The techniques have reached maturity. As shown by my own group's experience, grafts donated by living donors might provide the best short-term and longterm results. Debate persists about the optimal immunosuppression (IS), although the place of tacrolimus remains unchallenged. Tolerance induction protocols aiming to induce microchimerism have been tried in clinical transplantation without convincing results. Withdrawal of maintenance IS is possible in some children who underwent liver transplantation who have excellent clinical status and normal liver function tests but is not without risk of rejection and subsequent worsening of histology. The current trend favored by the Brussels' group is to minimize IS as soon after transplant as possible, aiming to obtain a state of "prope" or "almost" tolerance. Liver grafts are threatened in the long term by increasing hepatitis-related fibrosis, resulting most likely from immunological assault. Nowadays, the focus is on the longterm survival, quality of life (growth, academic performance, employment, self-fulfillment, fertility, raising a family, etc.), induction of tolerance, prevention of risks bound to decades of IS (nephrotoxicity and neurotoxicity, cardiovascular risk, de novo malignancies, etc.), and prevention of graft fibrosis. All these issues are fertile fields for younger scientists. Liver Transplantation 22 1284-1294 2016 AASLD.

A Comparison between splenic fossa and subhepatic fossa auxiliary partial heterotopic liver transplantation in a porcine model

To test the alternative possible locations for the placement of a liver graft and the relevant surgical technique issues, we developed a porcine model of auxiliary partial heterotopic liver transplantation (APHLT) and evaluated the difference between 2 styles of liver transplantation, either subhepatic fossa or splenic fossa APHLT, by comparing survival and biochemical indexes. Thirty-eight miniature pigs were randomly divided into 2 groups. A left hemihepatic graft without the middle hepatic vein (HV) was procured from the living donor. In group A (n = 9), an 8 mm diameter polytetrafluoroethylene (PTFE) graft approximately 2.5 cm long was connected to the left HV while another PTFE graft of the same size was connected to the left portal vein (PV). The liver graft was implanted in the right subhepatic fossa following splenectomy and right nephrectomy. In group B (n = 10), a PTFE graft of the same size was connected to the left HV while the liver graft was implanted in the splenic fossa following splenectomy and left nephrectomy. Survival rate and complications were observed at 2 weeks after transplantation. Data were collected from 5 animals in group A and 6 animals in group B that survived longer than 2 weeks. The liver function and renal function of the recipients returned to normal at 1 week after surgery in both groups. Eighty-eight percent (14/16) of the PTFE grafts remained patent at 2 weeks after surgery, but 44% of the PTFE grafts (7/16) developed mural thrombus. No significant differences in the survival rate and biochemistry were found between the 2 groups. In conclusion, the splenic fossa APHLT can achieve beneficial outcomes similar to the subhepatic fossa APHLT in miniature pigs, although it also has a high morbidity rate due to hepatic artery thrombosis, PV thrombosis, and PTEF graft mural thrombus formation. Liver Transplantation 22 812-821 2016 AASLD.

Auxiliary partial liver transplantation for acute liver failure using "high risk" grafts: Case report

Acute liver failure (ALF) is a reversible disorder that is associated with an abrupt loss of hepatic mass, rapidly progressive encephalopathy and devastating complications. Despite its high mortality, an emergency liver transplantation nowadays forms an integral part in ALF management and has substantially improved the outcomes of ALF. Here, we report the case of a 32-year-old female patient who was admitted with grade IV hepatic encephalopathy (coma) following drug-induced ALF. We performed an emergency auxiliary partial orthotopic liver transplantation with a “high risk” graft (liver macrovesicular steatosis approximately 40%) from a living donor. The patient was discharged on postoperative day 57 with normal liver function. Weaning from immunosuppression was achieved 9 mo after transplantation. A follow-up using CT scan showed a remarkable increase in native liver volume and gradual loss of the graft. More than 6 years after the transplantation, the female now has a 4-year-old child and has returned to work full-time without any neurological sequelae.

An update on liver transplantation: A critical review

Liver transplantation, although now a routine procedure, with defined indications and usually excellent outcomes, still has challenges. Donor shortage remains a key issue. Transplanted organs are not free of risk and may transmit cancer, infection, metabolic or autoimmune disease. Approaches to the donor shortage include use of organs from donors after circulatory death, from living donors and from those previously infected with Hepatitis B and C and even HIV for selected recipients. Normothermic regional and/or machine perfusion, whether static or pulsatile, normo- or hypothermic, are being explored and will be likely to have a major place in improving donation rates and outcomes. The main indications for liver replacement are alcoholic liver disease, HCV, non-alcoholic liver disease and liver cancer. Recent studies have shown that selected patients with severe alcoholic hepatitis may also benefit from liver transplant. The advent of new and highly effective treatments for HCV, whether given before or after transplant will have a major impact on outcomes. The role of transplantation for those with liver cell cancer continues to evolve as other interventions become more effective. Immunosuppression is usually required life-long and adherence remains a challenge, especially in adolescents. Immunosuppression with calcineurin inhibitors (primarily tacrolimus), antimetabolites (azathioprine or mycophenolate) and corticosteroids remains standard. Outcomes after transplantation are good but not normal in quality or quantity. Premature death may be due to increased risk of cardiovascular disease, de novo cancer, recurrent disease or late technical problems.

Future Economics of Liver Transplantation: A 20-Year Cost Modeling Forecast and the Prospect of Bioengineering Autologous Liver Grafts

During the past 20 years liver transplantation has become the definitive treatment for most severe types of liver failure and hepatocellular carcinoma, in both children and adults. In the U.S., roughly 16,000 individuals are on the liver transplant waiting list. Only 38% of them will receive a transplant due to the organ shortage. This paper explores another option: bioengineering an autologous liver graft. We developed a 20-year model projecting future demand for liver transplants, along with costs based on current technology. We compared these cost projections against projected costs to bioengineer autologous liver grafts. The model was divided into: 1) the epidemiology model forecasting the number of wait-listed patients, operated patients and postoperative patients; and 2) the treatment model forecasting costs (pre-transplant-related costs; transplant (admission)-related costs; and 10-year post-transplant-related costs) during the simulation period. The patient population was categorized using the Model for End-Stage Liver Disease score. The number of patients on the waiting list was projected to increase 23% over 20 years while the weighted average treatment costs in the pre-liver transplantation phase were forecast to increase 83% in Year 20. Projected demand for livers will increase 10% in 10 years and 23% in 20 years. Total costs of liver transplantation are forecast to increase 33% in 10 years and 81% in 20 years. By comparison, the projected cost to bioengineer autologous liver grafts is $9.7M based on current catalog prices for iPS-derived liver cells. The model projects a persistent increase in need and cost of donor livers over the next 20 years that’s constrained by a limited supply of donor livers. The number of patients who die while on the waiting list will reflect this ever-growing disparity. Currently, bioengineering autologous liver grafts is cost prohibitive. However, costs will decline rapidly with the introduction of new manufacturing strategies and economies of scale.

Monogenic diseases that can be cured by liver transplantation

While the prevalence of most diseases caused by single-gene mutations is low and defines them as rare conditions, all together, monogenic diseases account for approximately 10 in every 1000 births according to the World Health Organisation. Orthotopic liver transplantation (LT) could offer a therapeutic option in monogenic diseases in two ways: by substituting for an injured liver or by supplying a tissue that can replace a mutant protein. In this respect, LT may be regarded as the correction of a disease at the level of the dysfunctional protein. Monogenic diseases that involve the liver represent a heterogeneous group of disorders. In conditions associated with predominant liver parenchymal damage (i.e., genetic cholestatic disorders, Wilson's disease, hereditary hemochromatosis, tyrosinemia, α1 antitrypsin deficiency), hepatic complications are the major source of morbidity and LT not only replaces a dysfunctional liver but also corrects the genetic defect and effectively cures the disease. A second group includes liver-based genetic disorders characterised by an architecturally near-normal liver (urea cycle disorders, Crigler-Najjar syndrome, familial amyloid polyneuropathy, primary hyperoxaluria type 1, atypical haemolytic uremic syndrome-1). In these defects, extrahepatic complications are the main source of morbidity and mortality while liver function is relatively preserved. Combined transplantation of other organs may be required, and other surgical techniques, such as domino and auxiliary liver transplantation, have been attempted. In a third group of monogenic diseases, the underlying genetic defect is expressed at a systemic level and liver involvement is just one of the clinical manifestations. In these conditions, LT might only be partially curative since the abnormal phenotype is maintained by extrahepatic synthesis of the toxic metabolites (i.e., methylmalonic acidemia, propionic acidemia). This review focuses on principles of diagnosis, management and LT results in both paediatric and adult populations of selected liver-based monogenic diseases, which represent examples of different transplantation strategies, driven by the understanding of the expression of the underlying genetic defect.