Prognosis of Children Undergoing Liver Transplantation: A 30-Year European Study

Myosin Light Chain 9 Mediates Graft Fibrosis After Pediatric Liver Transplantation Through TLR4/MYD88/NF-κB Signaling

BACKGROUND & AIMS

The incidence of graft fibrosis is elevated after pediatric liver transplantation (pLT) and is influenced by cold ischemic time (CIT). Myosin light chain 9 (MYL9), a member of the myosin family, could act on hepatic stellate cells (HSCs) and induce a transition to active phase. We hypothesized that cold ischemic injury could stimulate MYL9 expression and lead to graft fibrosis.

METHODS

We tested the hypothesis by analyzing multi-omics data from human protocol liver biopsy samples 2 years after LT, performing rat LT with different CIT and conducting in vitro studies in HSC cell lines with MYL9 knockdown and overexpression.

RESULTS

Clinically, CIT is an independent risk factor for graft fibrosis after pLT. Omics analysis identified MYL9 as a prominent contributor in graft fibrosis. MYL9 is strongly correlated with liver fibrosis grade and the progression of fibrosis. The study of rat LT model demonstrated MYL9 expression increases with the prolongation of CIT, and its role is specific to transplant setting. Mechanistically, in vitro experiments with HSCs exposed to hypoxia/reoxygenation revealed a substantial decrease in HSCs activation after MYL9 knockdown. Conversely, overexpression of MYL9 significantly enhanced the activation of HSCs. Subsequent transcriptome sequencing of HSCs with MYL9 knockdown unveiled that MYL9 primarily functions through the TLR4/MYD88/NF-κB signaling pathway. Liver graft fibrosis was ameliorated when toll like receptor 4 signaling was inhibited in rats.

CONCLUSIONS

Our findings demonstrate that prolonged CIT up-regulates the expression of MYL9 in liver graft after LT. MYL9 activates HSCs and promotes fibrosis through a TLR4/MYD88/NF-κB signaling dependent manner.

Thresholds for conjugated hyperbilirubinaemia and hepatobiliary scintigraphy in biliary atresia: A 12-year national follow-up

AIM

To investigate liver biochemistry in infants screened for biliary atresia (BA) at the time of hepatobiliary scintigraphy (HS) and to evaluate the effect of change in threshold for HS.

METHODS

Infants born from 2010 to 2021, who underwent HS <6 months postpartum for BA, were included and data sourced from electronic medical records. The change in threshold in 2018 from ≥20 (and/or if conjugated bilirubin exceeds 20% of total bilirubin) to ≥17 μM (regardless of total bilirubin) was evaluated.

RESULTS

In the cohort of 635 infants, 48 had BA, 247 had AATD, and the remaining 343 were categorised as 'other'. After the threshold adjustment, HS timing was unaffected (p = 0.27), but the annual HS rate rose from 39 to 87, yet evaluations following the new guideline only accounted for 12%. All liver parameters were elevated in the BA group compared with the additional groups (p < 0.001). Amongst the 104 patients with non-excretory HS, gamma-glutamyl transferase (p < 0.001) and alanine aminotransferase (p = 0.002) remained elevated for BA. The lowest conjugated bilirubin measured in BA children was 36 μM.

CONCLUSION

After threshold change, HS use increased without earlier BA diagnostics, but most were not due to the new guideline. Alanine aminotransferase and gamma-glutamyl transferase should be considered in BA diagnostics.

Reappraisal of liver resection as an alternative to transplantation in locally advanced hepatoblastoma: A systematic review and analysis of pooled individual patient data

BACKGROUND

There is ongoing debate regarding liver transplantation (LT) versus liver resection (LR) for locally advanced hepatoblastoma. However, comparative studies are lacking. Consequently, a significant evidence gap persists, hindering the establishment of consensus guidelines. This study aimed to compare LT and LR for locally advanced hepatoblastoma, using predefined inclusion criteria to ensure comparable intervention groups.

METHODS

According to current Children's Oncology Group (COG) and SIOPEL (European Childhood Liver Tumour Study Group) recommendations, hepatoblastoma that requires LT evaluation was defined as either PRETEXT (PRE-Treatment EXTent of tumor) IV F+, POST-TEXT (POST-Treatment EXTent of tumor) IV, POST-TEXT P+, and/or POST-TEXT V+. A systematic literature search (Medline/Web-of-Science/Embase) was performed. Only patients who met the aforementioned criteria were included. Patient data were extracted individually and pooled.

RESULTS

A total of 189 patients with locally advanced hepatoblastoma from 55 studies met the specified criteria, with 111 undergoing LT and 78 LR. There were no significant differences between the two groups in age, alpha-fetoprotein (AFP), and PRETEXT stages. Local recurrence was more common after LR (14% vs. 3% in LT, p = .008), while distant recurrence was more often observed after LT (16% vs. 5% in LR, p = .035). Overall survival (OS) and event-free survival (EFS) did not differ significantly between LT and LR (5-year OS: LT = 75.3% [95% confidence interval: 66.5-85.2], LR = 87.6% [80.4-95.6], p = .140; 5-year EFS: LT = 68.5% [59.3-79.1], LR = 71.1% [60.7-83.3], p = .700).

CONCLUSION

Real-life data revealed that a considerable number of patients with locally advanced hepatoblastoma underwent LR. This analysis suggests that outcomes are similar and favorable for both approaches. LR can therefore be considered an effective alternative to LT in selected cases even in locally advanced hepatoblastoma.

Outcomes of Acute Kidney Injury After Pediatric Liver Transplantation: A 1-Year Follow-Up

BACKGROUND

Postoperative acute kidney injury (AKI) and chronic kidney disease (CKD) following pediatric liver transplantation (PLT) have not been comprehensively studied. This study aimed to evaluate the correlation between AKI and both 1-year CKD and mortality.

METHODS

This retrospective study included 132 children aged between 3 months and 12 years who underwent PLT between 2017 and 2021. Postoperative AKI and CKD after 1 year were assessed according to KDIGO criteria. AKI was classified as mild, moderate, or severe based on severity as well as transient (≤2 days) and persistent (>2 days) based on duration. CKD occurrence was the primary outcome, whereas all-cause mortality was the secondary outcome.

RESULTS

AKI developed in 45.4% of children, with 40.7% mild, 37.1% moderate, and 22.2% severe. Half of the children with AKI subsequently developed CKD within 1 year, compared to 23.1% without AKI. Multivariate analysis indicated that moderate AKI, severe AKI, and persistent AKI were risk factors for CKD development (moderate AKI, OR = 3.8, 95% CI = 1.2-12.3; severe AKI, OR = 7.4, 95% CI = 1.4-38.3; persistent AKI, OR = 9.7, 95% CI = 2.3-36.4). The overall mortality rate within 1 year after surgery was 9.8%. Children with severe AKI and AKI lasting longer than 2 days exhibited a higher mortality rate than those without AKI.

CONCLUSIONS

The development of postoperative AKI is relatively common after PLT, and the severity and duration of AKI are associated with CKD and mortality within 1 year.

Perioperative Complications After Pediatric Liver Transplantation-A Retrospective Analysis of 421 Cases

BACKGROUND

Due to the low incidence of pediatric liver transplantations, short- and long-term data regarding their outcome, details on early postoperative complications and their risk factors are under-represented in the literature.

METHODS

We retrospectively reviewed 1645 LTx performed at Hannover Medical School between January 2005 and December 2021. Of these, 421 transplantations were performed in 405 pediatric recipients. Univariate and multivariate binary logistic regressions were performed to identify independent risk factors for the onset of selected perioperative complications requiring intervention within the first 30 days following transplantation and their influence on graft and patient survival.

RESULTS

Pleural effusions represent the most common postoperative complication observed in 49.4% (n = 208) of cases, followed by vascular complications in 22.6% (n = 95) and biliary complications in 20.0% (n = 84) of cases. Donor age (OR: 1.019; p = 0.010) and recipient age between 3 and 12 years (OR: 1.849; p = 0.008) were identified as independent risk factors for the onset of pleural effusions. Retransplantations within the first year after LTx were necessary in 11.4% of all cases (n = 48). Twenty (4.8%) patients died within the first year after LTx.

CONCLUSION

Pleural effusions requiring postoperative intervention were observed in approximately half of the pediatric recipients. Therefore, the preemptive intraoperative placement of a chest drain under sterile conditions and general anesthesia should be considered. Our data further indicate that a two-stage procedure for biliary reconstruction may be the preferred procedure in patients at risk of early bile duct complications and retransplantation within the first year.

Intraoperative kidney replacement therapy in acute liver failure

Paediatric acute liver failure (PALF) is often characterised by its rapidity of onset and potential for significant morbidity and even mortality. Patients often develop multiorgan dysfunction/failure, including severe acute kidney injury (AKI). Whilst the management of PALF focuses on complications of hepatic dysfunction, the associated kidney impairment can significantly affect patient outcomes. Severe AKI requiring continuous kidney replacement therapy (CKRT) is a common complication of both PALF and liver transplantation. In both scenarios, the need for CKRT is a poor prognostic indicator. In adults, AKI has been shown to complicate ALF in 25-50% of cases. In PALF, the incidence of AKI is often higher compared to other critically ill paediatric ICU populations, with reports of up to 40% in some observational studies. Furthermore, those presenting with AKI regularly have a more severe grade of PALF at presentation. Observational studies in the paediatric population corroborate this, though data are not as robust-mainly reflecting single-centre cohorts. Perioperative benefits of CKRT include helping to clear water-soluble toxins such as ammonia, balancing electrolytes, preventing fluid overload, and managing raised intracranial pressure. As liver transplantation often takes 6-10 h, it is proposed that these benefits could be extended to the intraoperative period, avoiding any hiatus. Intraoperative CKRT (IoCKRT) has been shown to be practicable, safe and may help sicker recipients tolerate the operation with outcomes analogous with less ill patients not requiring IoCKRT. Here, we provide a comprehensive guide describing the rationale, practicalities, and current evidence base surrounding IoCKRT during transplantation in the paediatric population.

Long-term outcomes and risk factors for early bacterial infection after pediatric liver transplantation: a prospective cohort study

BACKGROUND

Liver transplantation (LT) is the most efficient treatment for pediatric patients with end-stage liver diseases, while bacterial infection is the leading reason for post-transplant mortality. The present study is to explore the outcomes and risk factors of early bacterial infection (within 1 months) after pediatric LT.

METHODS

In this prospective cohort study, 1316 pediatric recipients [median (IQR) age: 9.1 (6.3-28.0) months; male: 48.0%; median (IQR) follow-up time: 40.6 (29.1-51.4) months] who received LT from September 2018 to April 2022 were included. Bacterial culture samples such as sputum, abdominal drainage, blood, and so on were collected when recipients were presented with infective symptoms. Kaplan-Meier analysis was applied to estimate the long-term survival rates and logistic regression was used to identify independent risk factors. To explore the role of pretransplant rectal swab culture (RSC) in reducing post-transplant bacterial infection rate, 188 infant LT recipients [median (IQR) age: 6.8 (5.5-8.1) months; male: 50.5%] from May 2022 to September 2023 were included. Log-binomial regression was used to measure the association of pretransplant RSC screening and post-transplant bacterial infection. The 'Expectation Maximization' algorithm was used to impute the missing data.

RESULTS

Bacterial infection was the primary cause for early (38.9%) and overall mortality (35.6%) after pediatric LT. Kaplan-Meier analysis revealed inferior 1-year and 5-year survival rates for recipients with post-transplant bacterial infection (92.6 vs. 97.1%, 91.8 vs. 96.4%, respectively; P <0.001). Among all detected bacteria, Staphylococcus spp. (34.3%) and methicillin-resistant coagulase-negative Staphylococci (43.2%) were the dominant species and multidrug resistant organisms, respectively. Multivariable analysis revealed that infant recipients [adjusted odds ratio (aOR) 1.49; 95% CI: 1.01-2.20], male recipients (aOR, 1.43; 95% CI: 1.08-1.89), high graft-to-recipient weight ratio (aOR, 1.64; 95% CI: 1.17-2.30), positive post-transplant RSC (aOR, 1.45; 95% CI: 1.04-2.02) and nasopharyngeal swab culture (aOR 2.46; 95% CI: 1.72-3.52) were independent risk factors for early bacterial infection. Furthermore, RSC screening and antibiotic prophylaxis before transplantation could result in a relatively lower post-transplant infection rate, albeit without statistical significance (adjusted RR, 0.53; 95% CI: 0.25-1.16).

CONCLUSION

In this cohort study, post-transplant bacterial infection resulted in an inferior long-term patient survival rate. The five identified independent risk factors for post-transplant bacterial infection could guide the prophylaxis strategy of post-transplant bacterial infection in the future. Additionally, pretransplant RSC might decrease post-transplant bacterial infection rate.

Clinical Outcomes and Quality of Life of Patients Receiving Multi-Solid-Organ Transplants in Childhood Are Excellent: Results From a 20-Year Cohort Study

Advances in medicine allow children with previously fatal conditions to survive longer and present as transplant candidates; some requiring multiple solid-organ transplants (MSOT). There is limited data on clinical outcomes and no data on quality of life (QoL). In this mixed methods cohort study clinical outcomes from the NHSBT registry were analysed for all patients who received a kidney and one other solid-organ transplant as a child between 2000 and 2021 in the UK. QoL was measured using the PedsQL 3.0 Transplant Module questionnaire. 92 children met the inclusion criteria: heart/heart-lung and kidney (n = 15), liver and kidney (n = 72), pancreas and kidney (n = 4) and multivisceral (n = 1). Results showed excellent patient and graft survival, comparable to single-organ transplants. Allograft survival and rejection were significantly better in patients with combined liver and kidney transplants compared to patients with sequential liver and kidney transplants. QoL was excellent with a mean score of 74%. Key findings included a significant improvement in QoL post-transplant. This is the first study to look at clinical and QoL outcomes in MSOT recipients. The results indicate excellent long-term outcomes. All children born with conditions leading to end-stage disease in multiple solid-organs should be assessed as transplant candidates.

Surgical Site Infections After Pediatric Liver Transplantation-Impact of a Change in Perioperative Prophylactic Antibiotic Protocol

BACKGROUND

In spite of improved survival rates after pediatric liver transplantation, infections remain major contributors to perioperative morbidity and mortality. This study aimed to understand the impact of type and duration of perioperative antibiotic prophylaxis (PAP) on the occurrence of surgical site infections (SSIs).

METHODS

In total, 125 patients who underwent liver transplantation between 2014 and 2020 were retrospectively included. Patients were categorized into two periods based on changes in the standard PAP regimen. Risk factors for SSIs were investigated, including the influence of PAP duration, antibiotic substances used, and abdominal patch placement using multivariable regression models.

RESULTS

SSIs occurred in 23 (19%) of 119 analyzed patients and were not impacted by changes in the PAP regimen. The placement of an abdominal patch was a relevant risk factor for SSIs (odds ratio 3.81; 95% confidence interval [CI] 1.15-12.68). Longer PAP duration reduced the occurrence of SSIs by up to 4.6 percentage points (95% CI 0.0-9.1) per day, with its effect diminishing with longer duration. The choice of antibiotic substances for PAP changed after implementation of the new protocol, with a decline in vancomycin usage from 14% to 3%.

CONCLUSION

The results of this study emphasize the need for evidence-based PAP regimens tailored to the unique needs of pediatric liver transplant recipients. The occurrence of SSIs remains complex and is influenced by various factors beyond the PAP regimen. Multicentric efforts to develop effective prevention strategies against SSIs in this vulnerable population are warranted.

Determining the minimally clinically important difference for the pediatric liver transplant quality of life questionnaire

PURPOSE

The Pediatric Liver Transplant Quality of Life (PeLTQL) questionnaire is a disease-specific patient reported outcome measure for pediatric liver transplant (LT) recipients. To-date, threshold values above which a change in PeLTQL score is considered meaningful to patients are unavailable. This study proposes the first values for the minimally clinically important difference (MCID) for the PeLTQL.

METHODS

In this retrospective cohort study, anchor and distribution-based methods were used to estimate the MCID for the PeLTQL. Questionnaires completed between March 2013, and July 2022 were included if data from two sequential visits were available. An internal anchor question was used for anchor-based determination of the MCID. A final MCID estimate was ascertained from triangulation of all methods.

RESULTS

PeLTQL data from 65 LT recipients (26 [40%] male, 17 [42%] biliary atresia, median age at LT 3.08 years [interquartile range 0.99-7.30]), and their caregivers were included for analysis. Median patient age at time of baseline PeLTQL completion was 13.84 (10.90-15.86) years. The MCID for self-PeLTQL total scores ranged from 4.53 to 8.46, and from 4.47 to 8.85 for proxy responses. By triangulation, the MCID of the PeLTQL total score was 6.45 and 6.78 for self and proxy responses respectively.

CONCLUSION

A change in PeLTQL score of 6.5 or more points suggests a change in health status that is meaningful to the patient, providing the clinical team an opportunity to engage the patient's voice in reassessing current health status and management strategies.

Cognitive function of children with biliary atresia after primary living donor liver transplantation

BACKGROUND

The survival rate of children with biliary atresia (BA) after liver transplantation (LT) is significantly improved, and their quality of life has attracted much attention.This study aimed to investigate the cognition and its influencing factors in children with BA after primary living donor LT (BA-pLDLT) during infancy.

METHODS

Children with BA were recruited 6 months after pLDLT at Children's Hospital of Chongqing Medical University (2018-2022). Demographic and clinical data were collected from the health information system. Cognition was assessed using the Chinese version of the Griffiths Mental Development scale (GMDS-C). Multivariate linear regression were used to analyze the influencing factors of their cognitive function.

RESULTS

In total, 57 children with BA-pLDLT, aged 5.00(3.90-9.30) months at transplantation and 25.00(14.00-60.80) months at evaluation were included. The general developmental quotient (89.02 ± 12.07) and motor, language, eye-hand coordination, performance, and practical reasoning quotients of these children were significantly lower than the normative mean values of GMDS-C(P < 0.05). Of the 57 children, 16 (28.07%) had borderline developmental delay (DQ between 70 and 84), 3 (5.26%) had developmental delay (DQ < 70), and 11(19.29%) had language delay. Reoperation for biliary or vascular complications after pLDLT was a risk factor for decreased general development quotient and motor quotient and lower ZW at assessment was associated with decline motor quotient.

CONCLUSION

Children with BA-pLDLT have varying degrees of developmental delays in early life. Reoperation and nutritional deficiencies had adverse effects on cognitive development.

"Reduced Size Liver Grafts in Pediatric Liver Transplantation; Technical Considerations"

Liver transplantation (LT) has become a vital treatment option for children with end-stage liver disease. Left lateral segment (LLS) grafts are particularly common in split and living donor LT for pediatric patients. However, challenges arise in small infants receiving LLS grafts, primarily due to graft-size mismatches, resulting in "large-for-size" grafts. To overcome this issue, the practice of further reducing grafts from the LLS to diminish graft thickness has been explored. Currently, the indication for reducing the thickness of LLS grafts includes recipients with a body weight (BW) under 5.0 kg, neonates with acute liver failure, or those with metabolic liver disease. At the National Center for Child Health and Development in Tokyo, Japan, among 131 recipients of reduced-size LLS grafts, a remarkable 15-year graft survival rate of 89.9% has been achieved in small infants. This success indicates that with experience and refinement of the technique, there's a trend towards improved graft survival in recipients with reduced-thickness LLS grafts. This advancement underscores the importance of BW-appropriate methods in graft selection to ensure exceptional outcomes in vulnerable pediatric patients in need of LT. These techniques' ongoing development and refinement are crucial in enhancing the survival rates and overall outcomes for these young patients.

Utilization of older deceased donors for pediatric liver transplant may negatively impact long-term survival

BACKGROUND

Multiple adult studies have investigated the role of older donors (ODs) in expanding the donor pool. However, the impact of donor age on pediatric liver transplantation (LT) has not been fully elucidated.

METHODS

UNOS database was used to identify pediatric (≤18 years) LTs performed in the United States during 2002-22. Donors ≥40 years at donation were classified as older donors (ODs). Propensity analysis was performed with 1:1 matching for potentially confounding variables.

RESULTS

A total of 10,024 pediatric liver transplantation (PLT) patients met inclusion criteria; 669 received liver grafts from ODs. Candidates receiving OD liver grafts were more likely to be transplanted for acute liver failure, have higher Model End-Stage Liver Disease/Pediatric End-Stage Liver Disease (MELD/PELD) scores at LT, listed as Status 1/1A at LT, and be in the intensive care unit (ICU) at time of LT (all p < 0.001). Kaplan-Meier (KM) analyses showed that recipients of OD grafts had worse patient and graft survival (p < 0.001) compared to recipients of younger donor (YD) grafts. KM analyses performed on candidates matched for acuity at LT revealed inferior patient and graft survival in recipients of deceased donor grafts (p < 0.001), but not living donor grafts (p > 0.1) from ODs. Cox regression analysis demonstrated that living donor LT, diagnosis of biliary atresia and first liver transplant were favorable predictors of recipient outcomes, whereas ICU stay before LT and transplantation during 2002-12 were unfavorable.

CONCLUSION

Livers from ODs were used for candidates with higher acuity. Pediatric recipients of livers from ODs had worse outcome compared to YDs; however, living donor LT from ODs had the least negative impact on recipient outcomes.

Association of iron overload with infectious complications in liver transplant recipients: a systematic review and meta-analysis

OBJECTIVE

This study was performed to examine the possible association of iron overload with infectious complications and survival among liver transplant recipients.

METHODS

We conducted a systematic review and meta-analysis of studies published in the PubMed, Embase, Web of Science, and Cochrane Library databases up to September 2022. Hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted to estimate the association of iron overload with infectious outcomes and overall survival after liver transplantation.

RESULTS

Eight studies involving 2817 recipients met the inclusion criteria. Iron overload was strongly associated with an increased risk of infection after liver transplantation (HR, 1.66; 95% CI, 1.03-2.68). An increase in the serum ferritin level was associated with an increased risk of infection after liver transplantation (HR, 1.44; 95% CI, 1.09-1.91). Iron overload was a significant predictor of worse overall survival (HR, 1.35; 95% CI, 1.11-1.64). In addition, a high serum ferritin level was significantly associated with an increased risk of death (HR, 1.34; 95% CI, 1.10-1.64).

CONCLUSION

Iron overload may be associated with a higher risk of infectious complications and a worse prognosis among liver transplant recipients.

Current status and future directions of liver transplantation for metabolic liver disease in children

Orthotopic liver transplantation (OLT) in the care of children with inborn errors of metabolism (IEM) is well established and represent the second most common indication for pediatric liver transplantation in most centers worldwide, behind biliary atresia. OLT offers cure of disease when a metabolic defect is confined to the liver, but may still be transformative on a patient's quality of life reducing the chance of metabolic crises causing neurological damage in children be with extrahepatic involvement and no "functional cure." Outcomes post-OLT for inborn errors of metabolism are generally excellent. However, this benefit must be balanced with consideration of a composite risk of morbidity, and commitment to a lifetime of post-transplant chronic disease management. An increasing number of transplant referrals for children with IEM has contributed to strain on graft access in many parts of the world. Pragmatic evaluation of IEM referrals is essential, particularly pertinent in cases where progression of extra-hepatic disease is anticipated, with long-term outcome expected to be poor. Decision to proceed with liver transplantation is highly individualized based on the child's dynamic risk-benefit profile, their family unit, and their treating multidisciplinary team. Also to be considered is the chance of future treatments, such as gene therapies, emerging in the medium term.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (1) pre-transplant evaluation

BACKGROUND

Liver transplantation is the state-of-the-art curative treatment in end-stage liver disease. Imaging is a key element for successful organ-transplantation to assist surgical planning. So far, only limited data regarding the best radiological approach to prepare children for liver transplantation is available.

OBJECTIVES

In an attempt to harmonize imaging surrounding pediatric liver transplantation, the European Society of Pediatric Radiology (ESPR) Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phase. This paper reports the responses on preoperative imaging.

MATERIAL AND METHODS

An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted and 22 institutions from 11 countries returned the survey. From 2018 to 2020, the participating centers collectively conducted 1,524 transplantations, with a median of 20 transplantations per center per annum (range, 8-60).

RESULTS

Most sites (64%) consider ultrasound their preferred modality to define anatomy and to plan surgery in children before liver transplantation, and additional cross-sectional imaging is only used to answer specific questions (computed tomography [CT], 90.9%; magnetic resonance imaging [MRI], 54.5%). One-third of centers (31.8%) rely primarily on CT for pre-transplant evaluation. Imaging protocols differed substantially regarding applied CT scan ranges, number of contrast phases (range 1-4 phases), and applied MRI techniques.

CONCLUSION

Diagnostic imaging is generally used in the work-up of children before liver transplantation. Substantial differences were noted regarding choice of modalities and protocols. We have identified starting points for future optimization and harmonization of the imaging approach to multicenter studies.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (2) intraoperative imaging

BACKGROUND

Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of intraoperative and postoperative complications. So far, only limited data regarding the best radiological approach to monitor children during liver transplantation is available.

OBJECTIVE

To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra- and postoperative phase. This paper reports the responses related to intraoperative imaging.

MATERIALS AND METHODS

An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey.

RESULTS

Intraoperative ultrasound (US) is used by all sites to assess the quality of the vascular anastomosis in order to ensure optimal perfusion of the liver transplant. Vessel depiction is commonly achieved using color Doppler (95.3%). Additional US-based techniques are employed by fewer centers (power angio mode, 28.6%; B-flow, 19%; contrast-enhanced US, 14.3%). Most centers prefer a collaborative approach, with surgeons responsible for probe handling, while radiologists operate the US machine (47.6%). Less commonly, the intraoperative US is performed by the surgeon alone (28.6%) or by the radiologist alone (23.8%). Timing of US, imaging frequency, and documentation practices vary among centers.

CONCLUSION

Intraoperative US is consistently utilized across all sites during pediatric liver transplantation. However, considerable variations were observed in terms of the US setup, technique preferences, timing of controls, and documentation practices. These differences provide valuable insights for future optimization and harmonization studies.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (3) postoperative imaging

BACKGROUND

Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of postoperative complications. So far, limited data is available regarding the best radiologic approach to monitor children after liver transplantation.

OBJECTIVE

To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phases. This paper reports the responses related to postoperative imaging.

MATERIALS AND METHODS

An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey.

RESULTS

All sites commence ultrasound (US) monitoring within 24 h after liver transplantation. Monitoring frequency varies across sites, ranging from every 8 h to 72 h in early, and from daily to sporadic use in late postoperative phases. Predefined US protocols are used by 73% of sites. This commonly includes gray scale, color Doppler, and quantitative flow assessment. Alternative flow imaging techniques, contrast-enhanced US, and elastography are applied at 31.8%, 18.2%, and 63.6% of sites, respectively. Computed tomography is performed at 86.4% of sites when clarification is needed. Magnetic resonance imaging is used for selected cases at 36.4% of sites, mainly for assessment of biliary abnormalities or when blood tests are abnormal.

CONCLUSION

Diagnostic imaging is extensively used for postoperative surveillance of children after liver transplantation. While US is generally prioritized, substantial differences were noted in US protocol, timing, and monitoring frequency. The study highlights potential areas for future optimization and standardization of imaging, essential for conducting multicenter studies.

Pediatric Cholestatic Diseases: Common and Unique Pathogenic Mechanisms

Cholestasis is the predominate feature of many pediatric hepatobiliary diseases. The physiologic flow of bile requires multiple complex processes working in concert. Bile acid (BA) synthesis and excretion, the formation and flow of bile, and the enterohepatic reuptake of BAs all function to maintain the circulation of BAs, a key molecule in lipid digestion, metabolic and cellular signaling, and, as discussed in the review, a crucial mediator in the pathogenesis of cholestasis. Disruption of one or several of these steps can result in the accumulation of toxic BAs in bile ducts and hepatocytes leading to inflammation, fibrosis, and, over time, biliary and hepatic cirrhosis. Biliary atresia, progressive familial intrahepatic cholestasis, primary sclerosing cholangitis, and Alagille syndrome are four of the most common pediatric cholestatic conditions. Through understanding the commonalities and differences in these diseases, the important cellular mechanistic underpinnings of cholestasis can be greater appreciated.

Immunosuppression-Free Life after Pediatric Liver Transplant: A Case-Control Study from the Society of Pediatric Liver Transplant (SPLIT) Registry

OBJECTIVE

To compare long-term outcomes of pediatric liver transplant (LT) recipients off immunosuppression (IS) with matched controls on IS using data from the Society of Pediatric Liver Transplant (SPLIT) registry.

STUDY DESIGN

This was a retrospective case-control study. SPLIT participants <18 years of age, ≥4 years after isolated LT, and off IS for ≥1 year (cases) were age- and sex-matched 1:2 to patients with the same primary diagnosis and post-LT follow-up duration (controls). Primary outcomes included retransplantation, allograft rejection, IS comorbidities, and prevalence of SPLIT-derived composite ideal outcome (c-IO) achieved at the end of the follow-up period. Differences were compared using multiple linear regression for continuous outcomes and logistic regression for dichotomous data.

RESULTS

The study cohort was composed of 33 cases (42.4% male, 60.6% biliary atresia, median age at LT of 0.7 [P25, P75, 0.5, 1.6] years, median IS withdrawal time of 9 [P25, P75, 6, 12] years after LT) and 66 age- and sex-matched controls. No cases required retransplantation. Cases and controls had similar growth parameters, laboratory values, calculated glomerular filtration rates, rates of post-transplant lymphoproliferative disease, graft rejection, and attainment of c-IO.

CONCLUSIONS

No differences in allograft rejection rates, IS complications, or c-IO prevalence were seen between SPLIT patients off IS and age- and sex-matched controls remaining on IS. Discontinuation of IS most commonly occurred in the context of rigorously designed IS withdrawal trials. The available sample size was small, affecting generalizability to the broader pediatric LT population.

Clinical practice recommendations on lipoprotein apheresis for children with homozygous familial hypercholesterolemia: an expert consensus statement from ERKNet and ESPN

Homozygous familial hypercholesterolaemia is a life-threatening genetic condition, which causes extremely elevated LDL-C levels and atherosclerotic cardiovascular disease very early in life. It is vital to start effective lipid-lowering treatment from diagnosis onwards. Even with dietary and current multimodal pharmaceutical lipid-lowering therapies, LDL-C treatment goals cannot be achieved in many children. Lipoprotein apheresis is an extracorporeal lipid-lowering treatment, which is well established since three decades, lowering serum LDL-C levels by more than 70% per session. Data on the use of lipoprotein apheresis in children with homozygous familial hypercholesterolaemia mainly consists of case-reports and case-series, precluding strong evidence-based guidelines. We present a consensus statement on lipoprotein apheresis in children based on the current available evidence and opinions from experts in lipoprotein apheresis from over the world. It comprises practical statements regarding the indication, methods, treatment targets and follow-up of lipoprotein apheresis in children with homozygous familial hypercholesterolaemia and on the role of lipoprotein(a) and liver transplantation.

Optimal graft size in pediatric living donor liver transplantation: How are children different from adults?

BACKGROUND

Pediatric liver transplantation is an established treatment for end-stage liver disease in children. However, it is still posing relevant challenges, such as optimizing the graft selection according to the recipient size. Unlike adults, small children tolerate large-for-size grafts and insufficient graft volume might represent an issue in adolescents when graft size is disproportionate.

METHODS

Graft-size matching strategies over time were examined in pediatric liver transplantation. This review traces the measures/principles put in place to prevent large-for-size or small-for-size grafts in small children to adolescents with a literature review and an analysis of the data issued from the National Center for Child Health and Development, Tokyo, Japan.

RESULTS

Reduced left lateral segment (LLS; Couinaud's segment II and III) was widely applicable for small children less than 5 kg with metabolic liver disease or acute liver failure. There was significantly worse graft survival if the actual graft-to-recipient weight ratio (GRWR) was less than 1.5% in the adolescent with LLS graft due to the small-for-size graft. Children, particularly adolescents, may then require larger GRWR than adults to prevent small-for-size syndrome. The suggested ideal graft selections in pediatric LDLT are: reduced LLS, recipient body weight (BW) < 5.0 kg; LLS, 5.0 kg ≤ BW < 25 kg; left lobe (Couinaud's segment II, III, IV with middle hepatic vein), 25 kg ≤ BW < 50 kg; right lobe (Couinaud's segment V, VI, VII, VIII without middle hepatic vein), 50 kg ≤ BW. Children, particularly adolescents, may then require larger GRWR than adults to prevent small-for-size syndrome.

CONCLUSION

Age-appropriate and BW-appropriate strategies of graft selection are crucial to secure an excellent outcome in pediatric living donor liver transplantation.

Long-Term Outcome Following Liver Transplantation for Primary Hepatic Tumors-A Single Centre Observational Study over 40 Years

The incidence of pediatric liver tumors in general has been rising over the last years and so is the number of children undergoing liver transplantation for this indication. To contribute to the ongoing improvement of pre- and post-transplant care, we aim to describe outcome and risk factors in our patient cohort. We have compared characteristics and outcome for patients transplanted for hepatoblastoma to other liver malignancies in our center between 1983 and 2022 and analysed influential factors on tumor recurrence and mortality using nominal logistic regression analysis. Of 39 children (16 f) who had transplants for liver malignancy, 31 were diagnosed with hepatoblastoma. The proportion of malignant tumors in the transplant cohort rose from 1.9% (1983-1992) to 9.1% in the current decade (p < 0.0001). Hepatoblastoma patients were transplanted at a younger age and were more likely to have tumor extent beyond the liver. Post-transplant bile flow impairment requiring intervention was significantly higher compared to our total cohort (48 vs. 24%, p > 0.0001). Hearing loss was a common side effect of ototoxic chemotherapy in hepatoblastoma patients (48%). The most common maintenance immunosuppression were mTor-inhibitors. Risk factors for tumor recurrence in patients with hepatoblastoma were higher AFP before transplant (AFP_pre-LTX), a low ratio of AFP_max to AFP_pre-LTX and salvage transplantation. Liver malignancies represent a rising number of indications for liver transplantation in childhood. Primary tumor resection can spare a liver transplant with all its long-term complications, but in case of tumor recurrence, transplantation might have inferior outcome. The rate of acute biopsy-proven rejections and biliary complications in comparison to our total transplant cohort needs further investigations.

Urea cycle disorders and indications for liver transplantation

Urea cycle disorders (UCD) are inborn errors of metabolism caused by deficiency of enzymes required to convert nitrogen from ammonia into urea. Current paradigms of treatment focus on dietary manipulations, ammonia scavenger drugs, and liver transplantation. The aim of this study was to describe the characteristics and indication of liver transplantation in UCD in a tertiary hospital. We performed a retrospective study of children with UCD seen in the period 2000-2021. Data was collected on clinical onset, hyperammonemia severity, evolution and liver transplantation. There were 33 patients in the study period, whose diagnosis were: ornithine transcarbamylase (OTC, n = 20, 10 females), argininosuccinate synthetase (ASS, n = 6), carbamylphosphate synthetase 1 (CPS1, n = 4), argininosuccinate lyase (ASL, n = 2) and N-acetylglutamate synthetase (NAGS, n = 1) deficiency. Thirty one were detected because of clinical symptoms (45% with neonatal onset). The other 2 were diagnosed being presymptomatic, by neonatal/family screening. Neonatal forms (n = 14) were more severe, all of them presented during the first week of life as severe hyperammonemia (mean peak 1,152 µmol/L). Seven patients died (6 at debut) and all survivors received transplantation. There was no mortality among the late forms. Of the 27 patients who did not die in the neonatal period, 16 (59%) received liver transplantationwith 100% survival, normal protein tolerance and usual need of citrulline supplementation. The transplant's metabolic success was accompanied by neurologic sequelae in 69%, but there was no progression of brain damage. Decision of continuous medical treatment in 11 patients appeared to be related with preserved neurodevelopment and fewer metabolic crises.