Routine Use of Auxiliary Partial Orthotopic Liver Transplantation for Children With Fulminant Hepatic Failure: Preliminary Report

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".

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.

Auxiliary liver transplantation for management of acute liver failure in children - Systematic review

INTRODUCTION

Liver transplantation (LT) remains the standard of care in the treatment of acute pediatric liver failure (PALF) for the replacement of a severely damaged native liver in patients who are unlikely to recover. However, this is burdened by the consequences of long-term immunosuppression. Auxiliary partial liver orthotopic transplantation (APOLT) has emerged as a possible improved approach, by providing a graft that assures liver function until the regeneration of the native liver occurs, and then allows for possible progression to immunosuppression withdrawal. No previous systematic review has assessed APOLT for PALF. The aim of this work is to provide information on survival, postoperative complications, and withdrawal of immunosuppression after APOLT for PALF.

METHODS

The study was carried out according to the recommendations of the preferred report items for systematic reviews and meta-analyzes (PRISMA). We searched several electronic databases until October 31st, 2020, using the search terms "acute liver failure", "auxiliary liver transplant" and the MESH term "liver failure, acute". All types of clinical publications that presented results on APOLT for PALF, in English or Portuguese, and restricted to humans and for children under 18 years old were included. The following exclusion criteria were applied: "follow-up time <6 months", "does not report complications" and "does not report immunosuppression regimen (double vs triple)". Demographic data, clinical characteristics at the time of surgery and postoperative results were analyzed.

RESULTS

A total of 14 references (including 45 patients) were selected, including 3 case series (6-20 patients) and 11 case reports. Of the 45 subjects, 33 (73.3%) were male and 12 (26.7%) female. In most cases (n = 30; 66.7%), the cause of PALF was undetermined. All patients underwent APOLT. Their median age was 9 (range 0.6-17) years. In the postoperative period, the immunosuppression regimen was double in 34 (75.6%) and triple in 11 (24.4%) individuals. The main postoperative complications were rejection and infection. Over a follow-up period of 6 months to 14 years, 10 (22.2%) patients died. The main cause of death was sepsis (70%). Six (13.3%) patients were retransplanted. Of the survivors (n = 35), 68.6% achieved complete withdrawal from the immunosuppression regimen.

CONCLUSION

Based on current published evidence, APOLT for the treatment of PALF is a safe option, with an acceptable rate of complications and mortality. It has the great advantage of providing an immunosuppression-free life in the majority (68.6%) of survivors.

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.

Regeneration and Cell Recruitment in an Improved Heterotopic Auxiliary Partial Liver Transplantation Model in the Rat

BACKGROUND

Auxiliary partial liver transplantation (APLT) in humans is a therapeutic modality used especially to treat liver failure in children or congenital metabolic disease. Animal models of APLT have helped to explore therapeutic options. Though many groups have suggested improvements, standardizing the surgical procedure has been challenging. Additionally, the question of whether graft livers are reconstituted by recipient-derived cells after transplantation has been controversial. The aim of this study was to improve experimental APLT in rats and to assess cell recruitment in the liver grafts.

METHODS

To inhibit recipient liver regeneration and to promote graft regeneration, we treated recipients with retrorsine and added arterial anastomosis. Using green fluorescence protein transgenic rats as recipients, we examined liver resident cell recruitment within graft livers by immunofluorescence costaining.

RESULTS

In the improved APLT model, we achieved well-regenerated grafts that could maintain regeneration for at least 4 weeks. Regarding the cell recruitment, there was no evidence of recipient-derived hepatocyte, cholangiocyte, or hepatic stellate cell recruitment into the graft. Macrophages/monocytes, however, were consistently recruited into the graft and increased over time, which might be related to inflammatory responses. Very few endothelial cells showed colocalization of markers.

CONCLUSIONS

We have successfully established an improved rat APLT model with arterial anastomosis as a standard technique. Using this model, we have characterized cell recruitment into the regenerating grafts.

Postoperative imaging findings in children with auxiliary partial orthotopic liver transplant (APOLT)

Auxiliary partial orthotopic liver transplant (APOLT) is a treatment technique for people who have acute hepatic failure secondary to fulminant hepatic failure and might ultimately recover normal liver function. This surgical procedure is complicated, involving the placement of a liver graft while maintaining viability of the remaining native portion of the liver. This method allows the native liver to recover hepatic function, therefore eliminating the need for long-term immunosuppression, as is typically needed in post-transplant settings. Postoperative imaging in these cases can be challenging given the complex anatomy, specifically the vascular anastomosis. Therefore it is important for radiologists and clinicians to be aware of the anatomy as well as the variable imaging appearances of the liver. We review the imaging findings in children who have undergone auxiliary partial orthotopic liver transplant (APOLT).

Longterm outcomes of auxiliary partial orthotopic liver transplantation in preadolescent children with fulminant hepatic failure

By preserving part of the native liver, auxiliary partial orthotopic liver transplantation (APOLT) provides the advantage of potential immunosuppression (ISP) withdrawal if the native liver recovers but has had limited acceptance, especially in the United States, due to technical complications and low rates of native liver regeneration. No previous study has evaluated APOLT specifically for preadolescent children with fulminant hepatic failure (FHF). This population might benefit especially based on greater capacity for liver regeneration. Data from 13 preadolescent children who underwent APOLT were compared to 13 matched controls who underwent orthotopic liver transplantation (OLT) for FHF from 1996 to 2013. There were no significant differences in patient demographics or survival between the 2 groups. However, all surviving OLT recipients (10/13) remain on ISP, while all but 1 surviving APOLT recipient (12/13) showed native liver regeneration, and the first 10 recipients (76.9%) are currently off ISP with 2 additional patients currently weaning. In our experience, APOLT produced excellent survival and high rates of native liver regeneration in preadolescent children with FHF. This represents the largest series to date to report such outcomes. Liberating these children from lifelong ISP without the downside of increased surgical morbidity makes APOLT an attractive alternative. In conclusion, we therefore propose that, with the availability of technical expertise and with the technical modifications above, APOLT for FHF should be strongly considered for preteenage children with FHF.

Regenerative liver surgeries: the alphabet soup of emerging techniques

New surgical procedures taking advantage of the regenerative abilities of the liver are being introduced as potential curative therapies to these patients either to provide auxiliary support while the native liver recovers or undergoes hypertrophy. For patients with hepatocellular carcinoma outside of the Milan criteria or bilobar colorectal metastases liver transplantation is not an option. Fulminant hepatic failure can be treated but requires life-long immunosuppression. These complex surgical procedures require high quality and directed imaging.

Temporary auxiliary partial orthotopic liver transplantation using a small graft for familial amyloid polyneuropathy

Donor shortage is a major issue in liver transplantation. We have successfully performed temporary auxiliary partial orthotopic liver transplantation (APOLT) using a small volume graft procured from a living donor for recipients with familial amyloid polyneuropathy (FAP). The aim of this study was to evaluate this procedure by comparing it with standard living donor liver transplantation (LDLT). We compared 13 recipients undergoing this procedure with 23 recipients undergoing a standard LDLT for the treatment of FAP. The estimated donor graft volume and the graft volume/recipient's standard liver volume ratio were significantly smaller in the temporary APOLT group than in the standard LDLT group. Postoperative complications were comparable, although the hospital stay was longer in the temporary APOLT group. All the patients safely underwent a remnant native liver resection about 2 months after their first operation in the temporary APOLT group. No symptoms related to FAP developed before the remnant liver resection, and no significant differences in graft and patient survival were observed between the two groups. We successfully performed temporary APOLT using a small volume liver graft without postoperative liver failure for FAP. Temporary APOLT for FAP might be a useful alternative procedure for expanding the donor pool for LDLT.

Auxiliary liver transplantation in children

PURPOSE OF REVIEW

Auxiliary liver transplantation (ALT) has developed as a technique for treating patients with acute liver failure. The surgical techniques of ALT have been refined and current patient survival appears to be similar to that observed with conventional liver replacement for acute liver failure.

RECENT FINDINGS

Our understanding of liver regeneration has improved with experience and it is possible to identify patient and disease groups that are more likely to regenerate and wean off immunosuppression after ALT. Withdrawal of immunosuppression is possible in at least two thirds of survivors up to 4 years post transplant. Young patients have most to gain in the long term from immunosuppression withdrawal. Documentation of liver regeneration should be performed by liver histology, nuclear medicine scanning and CT volumetry. Weaning should be gradual to allow for graft atrophy to avoid complications. ALT has also been utilised for the management of inborn errors of metabolism based in the liver and for other rare problems and these will be briefly addressed in the review.

SUMMARY

Auxiliary liver transplantation should be considered for the treatment of children with acute liver failure satisfying current criteria for liver transplantation.

Continuous veno-venous single-pass albumin hemodiafiltration in children with acute liver failure

OBJECTIVE

To investigate the applicability, efficacy, and safety of single-pass albumin dialysis in children.

DESIGN

Retrospective data review of uncontrolled clinical data.

SETTING

University-based pediatric intensive care unit collaborating with a local center for liver transplantation.

PATIENTS

Nine children, aged 2 to 15 yrs, who were treated with single-pass albumin dialysis for acute liver failure of various origins under a compassionate-use protocol between 2000 and 2006. All patients met high-urgency liver transplantation criteria.

INTERVENTIONS

Single-pass albumin dialysis was performed as rescue therapy for children with acute liver failure.

MEASUREMENTS AND MAIN RESULTS

The decrease in hepatic encephalopathy (grades 1-4) and the serum levels of bilirubin, bile acids, and ammonium were measured to assess the efficacy of detoxification. As a measure of liver synthesis function, thromboplastin time and fibrinogen were analyzed. The safety of the procedure was assessed by documenting adverse effects on mean arterial blood pressure, platelet count, and clinical course. Seven out of nine patients were bridged successfully to either native organ recovery (n = 1) or liver transplantation (n = 6), one of them twice. Six out of nine patients undergoing single-pass albumin dialysis (ten treatments) survived. In six patients, hepatic encephalopathy could be reduced at least by one degree. Ammonium, bilirubin, and bile acid levels decreased in all patients. One patient had an allergic reaction to albumin.

CONCLUSIONS

In childhood acute liver failure, treatment with single-pass albumin dialysis was generally well tolerated and seems to be effective in detoxification and in improving blood pressure, thus stabilizing the critical condition of children before liver transplantation and facilitating bridging to liver transplantation. It may be beneficial in avoiding severe neurologic sequelae after acute liver failure and thereby improve survival. Single-pass albumin dialysis is an inexpensive albumin-based detoxification system that is easy to set up and requires little training. Whether and to what extent single-pass albumin dialysis can support children with acute liver failure until native liver recovery remains unclear.

Pediatric liver transplantation for acute liver failure at a single center: a 10-yr experience

Children transplanted for ALF urgently require an optimal graft and have lower post-transplant survival compared with children transplanted for chronic liver disease. Over 10 yr, 33 consecutive children transplanted for ALF were followed. Demographics, encephalopathy, intubation, dialysis, laboratory values, graft type ABOI, XL (GRWR > 5%), DDSLT, LDLT and WLT were evaluated. Complications and survival were determined. ALF accounted for 33/201 (16.4%) of transplants during this period. Twelve of 33 received ABOI, five XL grafts, 18 DDSLT, and three LDLT. Waiting time pretransplant was 2.1 days. One- and three-yr patient survival in the ALF group was 93.4% and 88.9%, and graft survivals were 86.4% and 77.7%. Median follow-up was 1452 days. ABOI one- and three yr patient and graft survival in the ALF was 91.6% and 78.6%. No difference in graft or patient survival was noted in the ALF and chronic liver disease group or the ABOI and the ABO compatible group. A combination of ABO incompatible donor livers, XL grafts, DDSLT, LDLT and WLT led to a short wait time and subsequent graft and patient survival comparable to patients with non-acute disease.

Feasibility of auxiliary partial living donor liver transplantation for fulminant hepatic failure as an aid for small-for-size graft: single center experience

Auxiliary partial orthotopic liver transplantation (APOLT) or heterotopic auxiliary partial liver transplantation (HAPLT) was initially indicated for potentially reversible fulminant hepatic failure (FHF). We started auxiliary partial living donor liver transplantation (LDLT) for FHF in February 2002. Since then, 5 FHF patients (3 females and 2 males) underwent auxiliary partial LDLT: 3 cases of APOLT and 2 cases of HAPLT. All of them received a small-for-size graft: graft-to-recipient weight ratio (GRWR) < or = 1.0%. The etiologies of FHF were hepatitis B virus (HBV) in 1, Wilson's disease in 1, and unknown origin in 3 cases. Three were the acute type and 2 the subacute type of FHF. Median age was 45 years (range, 14-54 years). Blood type was identical in all cases. A left lobe graft was used in 4 instances and a right lobe graft in 1 case. Median GRWR was 0.74 (range, 0.42-0.85). Median follow-up was 42 months (range, 3 days to 70 months). Three of 5 patients (60%) were alive (at 42, 67, and 70 months) and 1 was free of immunosuppression after sufficient recovery of the native liver. Two cases succumbed: 1 at postoperative day 3 because of cytomegalovirus pneumonia and 1 at 10 months after APOLT because of sepsis. Complications were seen in all 5 patients: Relaparotomy for hemostasis in 3, decompression surgery of the abdominal cavity in 1, rehepaticojejunostomy in 1, and biliary strictures in 2 cases. Auxiliary partial LDLT may be a choice as an aid for a small-for-size graft in FHF.