Tailoring allocation policies and improving access to paediatric liver transplantation over a 16-year period

Update on pediatric liver transplantation in Europe 2022: An ELITA-ESPGHAN report

OBJECTIVES

The European Liver Transplant Registry (ELTR) has been collecting data on liver transplantation (LT) in Europe since 1968. The aim of this report is to outline the number, techniques utilized, indications for, and outcomes of pediatric LT (pLT) in Europe, focusing on the Year 2022 in comparison to the preceding 5 years.

METHODS

Data were obtained from ELTR and Eurotransplant (ET). Summary statistics were performed.

RESULTS

In 2022, 585 pLTs were performed in Europe. The annual number of pLT decreased for the third consecutive year. Living donor LT represented 34% (n = 201) of pLT. The proportion of living donation (LD) remained stable over time. The major indication for pLT in Europe is biliary atresia. Donor age is increasing overall and is associated with worse graft survival. Graft and patient survival were impacted by both types of donors and types of grafts, and were significantly worse after re-transplantation. Most graft failures (77%) and deaths (82%) occurred within the first 6 months after pLT.

CONCLUSION

Annual numbers of pLT in Europe are decreasing over time. Given that the proportion of LD has remained stable, the shortage of deceased donor organs may not be the major reason for this trend, and other factors play a role. A focus on improving perioperative care is needed because the risk of graft loss and mortality is highest in the first 6 months after transplantation. New techniques like ex-situ machine perfusion may help mitigate risks with declining quality of deceased donor liver grafts.

Exploring auxiliary liver transplantation in the era of transplant oncology-A proposal for a new liver splitting program (ALERT-50)

Total hepatectomy and liver transplantation have emerged as a game-changing strategy in the treatment of several liver-confined primary or metastatic tumors, opening a new era of transplant oncology. However, the expansion of indications is going to worsen the chronic scarcity of organs, and new strategies are needed to enlarge the donor pool. A possible source of organs could be developing split liver transplantation programs. We propose to refer donors aged 18-50 years unsuitable for pediatric patients and donors aged 50-60 years for split evaluation. This will generate new small left lateral grafts that can be used for resection and partial liver segment II-III transplantation with delayed total hepatectomy procedures, based on a national waiting list specifically for non-HCC oncologic patients. Centralized imaging review will streamline the donor-recipient matching process and address organizational challenges. Additionally, adopting an ex situ splitting technique during hypothermic oxygenated machine perfusion could further enhance logistical efficiency and improve graft viability. The proposed protocol (ALERT 50) will therefore promote the development of oncologic indications without affecting the standard waiting list and without competing with urgent or pediatric patients.

Positive Clinical, Neuropsychological, and Metabolic Impact of Liver Transplantation in Patients With Argininosuccinate Lyase Deficiency

Liver transplantation (LTx) is increasingly used in Urea Cycle Defects (UCDs) to prevent recurrent hyperammonemia and related neurological irreversible injury. Among UCDs, argininosuccinate lyase deficiency (ASLD) has a more complex phenotype than other UCDs, with long-term neurocognitive deficits. Therefore, the role of LTx in ASLD is still debated. The impact of LTx on nine patients with early-onset ASLD was assessed through pre- and post-LTx clinical, neuropsychological, MRI and biochemical evaluations. After LTx, no episodes of metabolic decompensations were reported. Neuropsychological evaluations documented significant improvement in cognitive/developmental functioning especially in patients transplanted in early childhood. Improvements were also highlighted in daily living skills and emotional-behavioral problems, with a reduction in attention disturbances and somatic complaints. Movement disorders resolved after LTx in patient transplanted in early childhood. Any patients developed epilepsy with stability of EEG alterations after LTx. A positive effect of LTx on other disease-related outcomes such as growth, diet, medications, hospitalizations, and long-term ASLD-related complications was highlighted. The primary biomarker argininosuccinic acid dramatically reduced in plasma after transplantation with a decreasing trend in CSF at long-term follow-up. Moreover, health-related quality of life improved after LTx, especially when assessed through MetabQoL, a tool designed for intoxication diseases such as ASLD. In conclusion, our study showed a global beneficial impact of LTx in early-onset ASLD patients to avoid episodes of hyperammonemia, and improve neurocognitive outcome, adaptive and behavioral deficits when performed in early childhood with a dramatic benefit in terms of quality of life.

Chinese clinical practice guidelines for pediatric split liver transplantation

Liver transplantation is an effective treatment for end-stage liver disease in children, and its clinical efficacy has been validated. Split liver transplantation (SLT) can effectively expand the donor liver pool for children. SLT for children has unique clinical characteristics and principles. Establishing technical operation specifications for pediatric SLT plays a significant role in improving clinical efficacy. In this paper, clinical practice guidelines on pediatric SLT were established in the aspect of donor and donor liver evaluation, donor-recipient matching, and ductal segmentation and reconstruction of donor liver, aiming to standardize the technical process, optimize surgical operational details, minimize the risk of complications of SLT for children, further promoting the rapid development of pediatric SLT in China.

Does the introduction of the acuity circle policy change split liver transplantation practice?

With the acuity circles (AC) policy aiming to reduce disparities in liver transplantation (LT) access, the allocation of high-quality grafts has shifted, potentially affecting the use and outcomes of split LT. Data from the United Network for Organ Sharing (UNOS) database (February 4, 2016, to February 3, 2024) were analyzed, including 1470 candidates who underwent deceased donor split LT, with 681 adult and 789 pediatric cases. The study periods were divided into pre-AC (February 4, 2016, to February 3, 2020) and post-AC (February 4, 2020, to February 3, 2024). The study assessed changes in split LT volumes and examined the impact of center practices. Both adult and pediatric split LTs decreased in the initial 3 years after the policy change, followed by an increase in the final year, with an overall 11.9% and 13.9% decrease between the eras. Adult female split LT cases remained consistent, ensuring access for smaller recipients. High-quality "splittable" livers were increasingly allocated to high MELD patients (MELD-Na ≥30). Despite the overall decrease in case volume, adult split LT volume increased in newly active living donor liver transplantation centers, with 6 centers increasing living donor liver transplantation volume by over 50.0%. Pediatric split LT volumes decreased despite additional priorities for pediatric candidates. The number of split LTs decreased in the initial period after the AC policy introduction, but there was a consistent need for small female candidates. In the adult population, living donor liver transplantation and split LT demonstrated a synergistic effect in boosting center transplant volumes, potentially improving access for female candidates who need small grafts.