Liver transplantation for fulminant liver failure in children

North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position Paper on the Diagnosis and Management of Pediatric Acute Liver Failure

ABSTRACT

Pediatric acute liver failure (PALF) is a rare, rapidly progressive clinical syndrome with significant morbidity and mortality. The phenotype of PALF manifests as abrupt onset liver dysfunction, which can be brought via disparate etiology. Management is reliant upon intensive clinical care and support, often provided by the collaborative efforts of hepatologists, critical care specialists, and liver transplant surgeons. The construction of an age-based diagnostic approach, the identification of a potential underlying cause, and the prompt implementation of appropriate therapy can be lifesaving; however, the dynamic and rapidly progressive nature of PALF also demands that diagnostic inquiries be paired with monitoring strategies for the recognition and treatment of common complications of PALF. Although liver transplantation can provide a potential life-saving therapeutic option, the ability to confidently determine the certainness that liver transplant is needed for an individual child has been hampered by a lack of adequately tested clinical decision support tools and accurate predictive models. Given the accelerated progress in understanding PALF, we will provide clinical guidance to pediatric gastroenterologists and other pediatric providers caring for children with PALF by presenting the most recent advances in diagnosis, management, pathophysiology, and associated outcomes.

Liver Transplant Listing in Pediatric Acute Liver Failure: Practices and Participant Characteristics

Liver transplant (LT) decisions in pediatric acute liver failure (PALF) are complex. Three phases of the PALF registry, containing data on 1,144 participants over 15 years, were interrogated to characterize clinical features associated with listing status. A decrease in the cumulative incidence of listing (P < 0.005) and receiving (P < 0.05) LT occurred without an increase in the cumulative incidence of death (P = 0.67). Time to listing was constant and early (1 day; quartiles 1-3 = 0-2; P = 0.88). The most frequent reasons for not listing were "not sick enough" and "medically unsuitable." Participants listed for LT were more likely male, with coma grade scores >0; had higher international normalized ratio, bilirubin, lactate, and venous ammonia; and had lower peripheral lymphocytes and transaminase levels compared to those deemed "not sick enough." Participants listed versus those deemed "medically unsuitable" were older; had higher serum aminotransferase levels, bilirubin, platelets, and albumin; and had lower lactate, venous ammonia, and lymphocyte count. An indeterminate diagnosis was more prevalent in listed participants. Ventilator (23.8%) and vasopressor (9.2%) support occurred in a significant portion of listed participants but less frequently than in those who were not "medically suitable." Removal from the LT list was a rare event. Conclusion: The cumulative incidence of listing for and receiving LT decreased throughout the PALF study without an increase in the cumulative incidence of death. While all participants fulfilled entry criteria for PALF, significant differences were noted between participants listed for LT and those deemed "not sick enough" as well as those who were "medically unsuitable." Having an indeterminate diagnosis and a requirement for cardiopulmonary support appeared to influence decisions toward listing; optimizing listing decisions in PALF may reduce the frequency of LT without increasing the frequency of death.

Diffuse liver diseases in neonatal and pediatric liver transplant candidates: a pictorial essay

A wide spectrum of common and uncommon diffuse liver diseases affecting neonatal and pediatric liver transplant candidates is presented and analyzed using 16 and 64 multi-detector row helical CT (MDCT) and 1.5 T MRI fast imaging. Correlation of imaging findings and explanted liver or histology is illustrated in representative cases. Associated uncommon congenital anomalies are shown. In conclusion, in pediatric liver transplant candidates, 16-MDCT and 1.5 T fast MRI are useful for diagnosis and staging of liver disease, as well as for the evaluation of associated congenital anomalies.

Imaging in liver transplantation

The aim of this study was to illustrate the role of non-invasive imaging tools such as ultrasonography, multi-detector row computed tomography, and magnetic resonance imaging in the evaluation of pediatric and adult liver recipients and potential liver donors, and in the detection of potential complications arising from liver transplantation.

Pediatric acute liver failure with molecular adsorbent recirculating system treatment

BACKGROUND

The prognosis of pediatric acute liver failure (PALF) has been significantly improved by emergency orthotopic liver transplantation (OLT). Since 2004, the molecular adsorbent recirculating system (MARS) has been proposed as a bridging procedure. The aim of our study was to assess its efficacy in children with PALF.

PATIENTS AND METHODS

Since 1999 we performed treatment of 39 fulminant hepatic failure (FHF) cases with MARS. Since September 2004 we treated 6 pediatric patients with FHF who were of mean age 10.6 years (range, 3-15 years) including 4 females and 2 males. In 3 cases the cause of FHF was unknown; in 2 cases, it was induced by paracetamol overdose; and in 1, by acute hepatitis B virus. Inclusion criteria were: bilirubin >15 mg/dL; creatinine >or=2 mg/dL; encephalopathy grade >II; and International normalized ratio (INR) >2.5. Other estimated parameters were: AST and ALT serum levels, lactate, and urine volume. Neurological status was monitored using the Glasgow Coma Scale (GCS). Continuous MARS treatment was performed in all patients with a kit change every 8 hours. Intensive care unit (ICU) treatment was applied to optimize regeneration and to prevent cardiovascular complications.

RESULTS

We observed a significant improvement among levels of bilirubin (P< .009), ammonia (P< .005), creatinine (P< .02), GCS (P< .002), and predictive criteria and as Sequential Organ Failure Assessment (SOFA) and Pediatric End-Stage Liver Disease (PELD). Three children underwent OLT: 1 died after 5 days due to primary nonfunction and 2 children are alive after a median follow-up of 14 months. In 2 children the MARS treatment led to resolution of clinical status without liver transplantation. One child died before OLT due to sepsis and multiorgan failure.

CONCLUSIONS

We concluded that application of the MARS liver support device in combination with experienced ICU management contributed to improve the clinical status in children with PALF awaiting liver transplantation.

Liver support for fulminant hepatic failure: is it time to use the molecular adsorbents recycling system in children?

OBJECTIVE

To describe the main liver support devices used for fulminant hepatic failure (FHF) and to review data on the Molecular Adsorbents Recycling System (MARS) and assess its efficiency in children.

DATA SOURCE

Studies were identified through selected readings and a MEDLINE search from 1975 and 2004 using fulminant hepatic failure, acute liver failure, primary graft dysfunction, liver support, MARS, and extracorporeal liver assist device as key words.

STUDY SELECTION

All original studies, including case reports, relating to the use of the MARS or albumin dialysis system were included. Additional attention was put on prognosis criteria of FHF severity in children.

DATA EXTRACTION

Study design, numbers and diagnoses of patients, definite or bridging treatment, outcome measures, and complications were extracted and compiled. Results of individual trials were combined on the risk ratio scale.

DATA SYNTHESIS

Nine randomized trials including 354 patients were identified. However, liver support failed to significantly affect mortality when compared with standard medical therapy. Albumin dialysis, and particularly MARS, emerges as an easily applicable technique for temporary liver support. Some well-designed studies have characterized its efficiency in a few indications, such as in intractable pruritus in chronic liver disease, in acute or chronic liver diseases, and in decompensated cirrhosis with hepatorenal syndrome. In adults and children with FHF, anecdotal reports suggest that MARS may stabilize the patient. However, no randomized controlled study has validated its use in this indication. A randomized controlled study is ongoing in adults with FHF. Such a trial seems to be unfeasible in children for several methodologic reasons.

CONCLUSIONS

Although promising preliminary results suggest that MARS may have a significant position in the therapeutic arsenal for FHF, no sufficient data exist to justify its use in children. For as long as the results of the ongoing adult trial are not available, the indications of this expensive technique in children with FHF are limited.

Liver transplantation for fulminant hepatitis at Stanford University

BACKGROUND

To review the clinical characteristics and outcomes of 26 patients evaluated for liver transplantation for fulminant hepatic failure at Stanford University and Lucile Packard Children's Hospital in an attempt to identify risk factors and prognostic predictors of survival.

METHODS

A retrospective review of the records of 26 consecutive patients who were evaluated for possible liver transplantation for acute liver failure from May 1, 1995, to January 1, 2000. Pretransplant patient demographics and clinical characteristics were collected, and the data were analyzed by univariate and multivariate analysis.

RESULTS

Clinical assessment of encephalopathy did not predict outcome. Patients with abnormal computed tomography (CT) of the brain had a twofold increase in mortality compared with those patients with normal studies (p = 0.03). Patients requiring mechanical ventilation and continuous venovenous hemofiltration (CVVH) also had a poor prognosis.

CONCLUSION

Predictors of poor outcome after fulminant hepatic failure include abnormal CT scan, mechanical ventilation, and requirement for hemofiltration.

Orthotopic liver transplantation in liver-based metabolic disorders

The efficacy of orthotopic liver transplantation (OLT) in the management of more common liver-based metabolic disorders associated with severe liver damage, alpha-1-antitrypsin deficiency (PIZZ), Wilson disease and tyrosinaemia has been demonstrated and indications defined. An early mortality in excess of 15% and finite resources limit its use. Phenotypic heterogeneity make the precise indication in other disorders less certain. In disorders in which endstage liver disease is less frequent such as cystic fibrosis, haemochromatosis and galacosaemia it has been a very effective therapy. It has been used with encouraging results in disorders in which the liver is structurally normal such as Crigler-Najjar type I, primary hyperoxaluria type I and primary hypercholesterolaemia. In these it should be performed before there is permanent damage to brain, kidneys or heart. OLT in the short term prevents hyperammonaemic coma in urea cycle defects and may prevent extrahepatic disease in glycogen storage disease type IV. Its limitation in reversing all metabolic effects in these and other disorders is discussed. It is ineffective in protoporphyria or Niemann Pick disease type II (Sea Blue Histiocyte syndrome) in which the transplanted liver acquires the lesions of the initial disorder and extrahepatic features progress. Early referral provides optimum circumstances to assess the benefits of OLT as compared with those of other forms of management and to achieve transplantation at the ideal time. The place of OLT in management will require constant review as metabolic disorders are better defined, new forms of therapy evolve and as techniques of liver transplantation and modes of immunosuppression improve.