Outcomes following liver transplantation in young infants: Data from the SPLIT registry

Ischemia and reperfusion-injured liver-derived exosomes elicit acute lung injury through miR-122-5p regulated alveolar macrophage polarization

Acute lung injury (ALI) is a common postoperative complication, particularly in pediatric patients after liver transplantation. Hepatic ischemia-reperfusion (HIR) increases the release of exosomes (IR-Exos) in peripheral circulation. However, the role of IR-Exos in the pathogenesis of ALI induced by HIR remains unclear. Here, we explored the role of exosomes derived from the HIR-injured liver in ALI development. Intravenous injection of IR-Exos caused lung inflammation in naive rats, whereas pretreatment with an inhibitor of exosomal secretion (GW4869) attenuated HIR-related lung injury. In vivo and in vitro results show that IR-Exos promoted proinflammatory responses and M1 macrophage polarization. Furthermore, miRNA profiling of serum identified miR-122-5p as the exosomal miRNA with the highest increase in young rats with HIR compared with controls. Additionally, IR-Exos transferred miR-122-5p to macrophages and promoted proinflammatory responses and M1 phenotype polarization by targeting suppressor of cytokine signaling protein 1(SOCS-1)/nuclear factor (NF)-κB. Importantly, the pathological role of exosomal miR-122-5p in initiating lung inflammation was reversed by inhibition of miR-122-5p. Clinically, high levels of miR-122-5p were found in serum and correlated to the severity of lung injury in pediatric living-donor liver transplant recipients with ALI. Taken together, our findings reveal that IR-Exos transfer liver-specific miR-122-5p to alveolar macrophages and elicit ALI by inducing M1 macrophage polarization via the SOCS-1/NF-κB signaling pathway.

The impact of portal vein reconstruction on portal vein complications after pediatric living-donor liver transplantation with left lobe graft

BACKGROUND

This study aimed to determine whether the different methods of portal vein reconstruction have an impact on the occurrence of portal vein complications after pediatric living-donor liver transplantation with left lobe graft.

METHODS

A total of 567 recipients were eligible for enrollment in this study and were divided into the following 2 groups according to the type of portal vein reconstruction: group 1 underwent anastomosis of the left and right bifurcations of the recipient portal vein to the donor portal vein (type 1), whereas group 2 underwent anastomosis of the bevel formed by the main trunk and right branch of the recipient portal vein to the donor portal vein (type 2). Postoperative portal vein complications and recipient and graft survival rates were compared between the 2 groups before and after propensity score matching.

RESULTS

Portal vein complications occurred in 53 (9.3%) patients, including 46 recipients with portal vein stenosis and 7 with portal vein thrombosis. After propensity score matching, the incidence of portal vein stenosis in group 2 was lower than that in group 1 (P = .035). The first diagnosis time of portal vein stenosis in group 2 was later than that in group 1 (P = .033), and the incidence of early portal vein stenosis was lower than that in group 1 (P = .009). There were no statistically significant differences in the incidence of portal vein thrombosis and recipient and graft survival rates between the 2 groups.

CONCLUSIONS

Type 2 portal vein reconstruction appears to be a viable technique in pediatric living-donor liver transplantation with left lobe graft that can effectively reduce the incidence of portal vein stenosis.

Impact of donor age on short-term outcomes after pediatric split liver transplantation

Background

Donor shortage is an important limitation of liver transplantation (LT). Split liver transplantation (SLT) may increase the sources of donors and reduce the problem of organ shortage. However, there are no standard criteria of the selection of SLT donor, especially regarding the donor age.

Methods

We retrospectively analyzed the clinical data of children who received initial SLT between January 2015 and December 2021. Based on the age of donors, the patients were divided into groups A (1-10 years old; n = 26), B (10-45 years old; n = 87), and C (45-55 years old; n = 27). The short-term (<1 year after SLT) outcomes of the recipients were analyzed.

Results

A total of 140 patients received SLT from 122 donors. The 1-, 3- and 12-month patient survival rates in group A were 100.0%, and the graft survival rates were 92.3%. The 1-, 3- and 12-month survival rates of patient and graft in group B were 97.7%, 96.6%, and 95.0%, respectively, and in group C were 85.2%, 85.2%, and 81.1%, respectively. The patient survival rate was significantly lower in group C than in groups A and B (p = 0.0082). There was no significant difference in graft survival between the three groups (p = 0.0545).

Conclusions

Similar results were obtained for pediatric SLT with donors <10 years old and 10-45 years old. Pediatric SLT can be performed with older donors (45-55 years) after strict donor selection and selection of appropriate recipients.

The impact of low recipient weight [≤ 7kg] on long-term outcomes in 1078 pediatric living donor liver transplantations

BACKGROUND

infants who require liver transplantation represent a treatment challenge because chronic liver disease at this early age affects the child's growth and development during a critical phase. The aim is to compare demographics, operative data, and long-term outcomes according to recipient weight at the time of LDLT.

METHODS

This retrospective study included primary LDLT analyzed in 2 groups: BW ≤ 7 kg (n = 322) and BW > 7 kg (n = 756). A historical comparison between periods was also investigated.

RESULTS

BW ≤ 7 kg had significantly lower height/age and weight/age z-scores, with median PELD score of 19. Transfusion rates were higher in the BW ≤ 7 kg group (30.9 ml/kg versus 15.5 ml/kg, P < 0.001). Higher frequencies of PV complications were seen in the BW ≤ 7 kg cohort. HAT and retransplantation rates were similar. Those with BW ≤ 7 kg required longer ICU and hospital stays. Patient and graft survival were similar. Patient survival in BW≤ 7 kg was significantly better in the most recent period.

CONCLUSION

Malnutrition and advanced liver disease were more frequent in BW ≤ 7 kg. Despite increased rates of PVT and longer hospital stay, patient and graft long-term survival were similar between groups.

Management and outcome of hepatic artery thrombosis with whole-liver transplantation using donors less than one year of age

BACKGROUND/PURPOSE

The incidence of hepatic artery thrombosis (HAT) in recipients is high after pediatric LT using young donors. In this study we investigated the management and outcome of HAT after whole-LT using donors less than one year of age. And evaluate the safety of pediatric donors, and increase the utilization of pediatric donors overall.

METHODS

We retrospectively analyzed the clinical data encompassing children who underwent whole-liver transplantation in our department from January 2014 to December 2019. Recipients receiving a liver from a donor ≥1 month and ≤12 months were included, and a total of 110 patients were included in this study.

RESULTS

The results showed an incidence for HAT of 20% and the median time to HAT diagnosis was 3.0 (2.0, 5.3) days post-operation. Anticoagulant therapy was used for 19 cases and 94.7% of them achieved hepatic artery recanalization or collateral formation. The median time of recanalization was 12 (5, 15) days. Bile leakage and biliary strictures occurring in the HAT group were higher than in the non HAT group (13.6% vs. 1.1% and 31.8% vs. 3.4%). There were no significant differences in the survival rates of recipients or grafts among the two groups (P = 0.474, P = 0.208, respectively).

CONCLUSION

We confirmed that the incidence of HAT in LT recipients use donors less than 1 year is high, but recanalization can be performed using anticoagulant therapy. Although biliary complications increased significantly after HAT, the survival rates of patients and grafts were satisfactory.

LEVEL OF EVIDENCE

Level III.

Liver Transplantation in Children with Urea Cycle Disorders: The Importance of Minimizing Waiting Time

Liver transplantation (LT) for children with urea cycle disorders (UCDs) is capable of correcting the enzymatic defect and preventing progressive neurologic injury. We describe the characteristics and outcomes of pediatric LT recipients with UCDs. We identified all pediatric (<18 years) LT candidates with UCDs in the United Network for Organ Sharing (UNOS) database (February 2002 to September 2020). Multivariable Cox and logistic regression were used to determine risk factors for graft loss and cognitive delay, respectively. Of 424 patients, 1.9% (8/424) experienced waitlist mortality and 95.0% underwent LT (403/424). The most frequently encountered UCDs in our cohort were ornithine transcarbamylase deficiency (46.2%), citrullinemia (20.3%), and argininosuccinic aciduria (ASA; 12.9%). The 1-, 3-, and 5-year graft survival rates were 90.4%, 86.3%, and 85.2%, respectively. Multivariable analysis showed a decreased risk of graft loss with increasing weight at LT (adjusted hazard ratio [aHR], 0.96; 95% confidence interval [CI], 0.94-0.99; P = 0.02), male sex (aHR, 0.49; 95% CI, 0.28-0.85; P = 0.01), and ASA diagnosis (aHR, 0.29; 95% CI, 0.09-0.98; P = 0.047), when adjusting for location (intensive care/hospital/home) and graft type (both P ≥ 0.65). In multivariable logistic regression, waitlist time (adjusted odds ratio [aOR], 1.10; 95% CI, 1.02-1.17; P = 0.009) and male sex (aOR, 1.71; 95% CI, 1.02-2.88; P = 0.04) were associated with increased odds of long-term cognitive delay. Waitlist duration is associated with a long-term risk of cognitive delay. Given excellent long-term outcomes, early LT evaluation should be considered in all children with UCDs to prevent progressive neurologic injury and optimize cognitive outcomes.

Secondary Malnutrition and Nutritional Intervention in Cholestatic Liver Diseases in Infants

We aimed to conduct an updated review on the pathophysiology, diagnosis, and nutritional intervention of CCLD and secondary malnutrition in infants. Protein-energy malnutrition, impaired linear growth, fat-soluble vitamin deficiencies, and hepatic osteodystrophy can occur in up to 80% of cases. The proposed pathophysiological mechanisms include insufficient energy intake, lipid- and fat-soluble vitamin malabsorption, increased energy expenditure, altered intermediate metabolism, hormonal dysregulation, and systemic inflammation. The current approach to diagnosis is the identification of the deviation of growth parameters, body composition, and serum concentration of micronutrients, which determines the type and magnitude of malnutrition. Currently, liver transplantation is the best therapeutic alternative for the reversal of nutritional impairment. Early and effective portoenteroanatomosis can extend survival in patients with biliary atresia. Medical and dietary interventions in some storage and metabolic diseases can improve liver damage and thus the nutritional status. A proportion of patients with biliary atresia have fat-soluble vitamin deficiencies despite receiving these vitamins in a water-soluble form. With aggressive enteral nutrition, it may be possible to increase fat stores and preserve muscle mass and growth. The nutritional issues identified in the pre- and post-transplantation stages include muscle mass loss, bone demineralization, growth retardation, and obesity, which seems to correspond to the natural history of CCLD. Due to the implications for the growth and development of infants with CCLD with this complex malnutrition syndrome, innovative projects are required, such as the generation of prediction and risk models, biomarkers of growth and body composition, and effective strategies for nutritional prevention and intervention.

Hepatic hydrothorax in a child and its management

Hepatic hydrothorax is a rare complication of portal hypertension. The optimal treatment for this condition is liver transplantation. Liver transplantation is significantly more manageable in children who weigh more than 8 kg. Here, an implantable pleural access device was used in a 5-month-old infant for painless iterative punctures to relieve respiratory symptoms, while waiting for liver transplantation and the patient's growth. The patient underwent successful transplantation 3 months later with a more optimal weight.

Survival and Complication of Liver Transplantation in Infants: A Systematic Review and Meta-Analysis

Background: Modern surgical techniques and scientific advancements have made liver transplant (LT) in infants feasible. However, there are only a small number of studies examining the short- as well as long-term outcomes of LT in this vulnerable subset of children. Methods: Comprehensive searches were done systematically through the PubMed, Scopus, and Google scholar databases. Studies that were retrospective record based or adopted a cohort approach and reported either patient survival rates or graft survival rates or complications of LT in infants were included in the meta-analysis. Statistical analysis was done using STATA version 13.0. Results: A total of 22 studies were included in the meta-analysis. The overall pooled patient survival rate at 1 year, >1-5 years, and >5 years post-transplantation was 85% (95% CI: 78--92%), 71% (95% CI: 59-83%), and 80% (95% CI: 69-91%), respectively. The overall pooled graft survival rate at 1 year, >1-5 years, and >5 years post-transplantation was 72% (95% CI: 68-76%), 62% (95% CI: 46-78%), and 71% (95% CI: 56-86%), respectively. The overall pooled rate for vascular complications, need for re-transplantation, biliary complications, and infection/sepsis was 12% (95% CI: 10-15%), 16% (95% CI: 12-20%), 15% (95% CI: 9-21%), and 50% (95% CI: 38-61%), respectively. Conclusion: The current meta-analysis showed modest patient and graft survival rates for infant liver transplantation. However, the complication rates related to infection/sepsis were high. More comprehensive evidence is required from studies with larger sample sizes and a longer duration of follow-up.