Impaired intention-to-treat survival after listing for liver transplantation in children with biliary atresia compared to other chronic liver diseases: 20 years' experience from the Nordic countries

Disparate Intent-to-Treat Outcomes for Pediatric Liver Transplantation Based on Indication

Background

The impact of indication for pediatric liver transplantation on waitlist and post-transplant mortality outcomes is well known, but the impact on intent-to-treat outcomes has not been investigated. Intent-to-treat survival analysis is important in this study because it is more comprehensive, combining the transplant outcomes of waitlist mortality, post-transplant mortality, and transplant rate into a single metric to elucidate any disparities in outcomes based on indication.

Methods

Cox regression was used to analyze factors impacting survival in 8,002 children listed for liver transplant in the UNOS database between 2006 and 2016. The Kaplan-Meier method and log-rank test were used to assess differences in waitlist, post-transplant, and intent-to-treat mortality among the top 5 indications of biliary atresia, acute hepatic necrosis, metabolic disorders, hepatoblastoma, and autoimmune cirrhosis.

Results

When compared to the reference group of biliary atresia, multivariate analyses showed that every indication was associated with inferior intent-to-treat outcomes except for metabolic disorders. Hepatoblastoma (hazard ratio (HR): 3.73), autoimmune cirrhosis (HR: 1.86), and AHN (HR: 1.77) were associated with significantly increased intent-to-treat mortality. Hepatoblastoma was also associated with increased post-transplant mortality (HR: 3.77) and was the only indication significantly associated with increased waitlist mortality (HR: 6.43).

Conclusion

Significant disparity exists across all indications with respect to an increased intent-to-treat mortality, along with an increased post-transplant and waitlist mortality, when compared to the biliary atresia reference group. If further studies validate these findings, a reexamination of the equitable distribution of allografts for transplant may be warranted as well as a focus on disparities in survival after transplant.

Variability of Care and Access to Transplantation for Children with Biliary Atresia Who Need a Liver Replacement

Background & Aims: Biliary atresia (BA) is the commonest single etiology indication for liver replacement in children. As timely access to liver transplantation (LT) remains challenging for small BA children (with prolonged waiting time being associated with clinical deterioration leading to both preventable pre- and post-transplant morbidity and mortality), the care pathway of BA children in need of LT was analyzed—from diagnosis to LT—with particular attention to referral patterns, timing of referral, waiting list dynamics and need for medical assistance before LT. Methods: International multicentric retrospective study. Intent-to-transplant study analyzing BA children who had indication for LT early in life (aged < 3 years at the time of assessment), over the last 5 years (2016−2020). Clinical and laboratory data of 219 BA children were collected from 8 transplant centers (6 in Europe and 2 in USA). Results: 39 patients underwent primary transplants. Children who underwent Kasai in a specialist -but not transplant- center were older at time of referral and at transplant. At assessment for LT, the vast majority of children already were experiencing complication of cirrhosis, and the majority of children needed medical assistance (nutritional support, hospitalization, transfusion of albumin or blood) while waiting for transplantation. Severe worsening of the clinical condition led to the need for requesting a priority status (i.e., Peld Score exception or similar) for timely graft allocation for 76 children, overall (35%). Conclusions: As LT currently results in BA patient survival exceeding 95% in many expert LT centers, the paradigm for BA management optimization and survival have currently shifted to the pre-LT management. The creation of networks dedicated to the timely referral to a pediatric transplant center and possibly centralization of care should be considered, in combination with implementing all different graft type surgeries in specialist centers (including split and living donor LTs) to achieve timely LT in this vulnerable population.

A paradigm shift in the intention-to-transplant children with biliary atresia: Outcomes of 101 cases and a review of the literature

For children with BA who do not benefit from Kasai surgery, the only therapeutic option is liver replacement and transplantation. The very decision to proceed for transplantation is a crucial point in time because it is the first step toward the preparation for the transplantation. The former time point is defined in this analysis as "intent-to-transplant" care pathway. In the life of every BA candidate for liver replacement, this point in time varies and mostly depends on the decision of their primary caring teams-about when to switch from supportive care to transplant, and thus to refer to a transplant center. This intent-to-transplant analysis of a series of 101 consecutive infants that were referred to a single transplant team showed that excellent overall outcome (97% survival) has been achieved overall. However, three deaths occurred that were clearly related to a late referral. This analysis and recent observations from other centers strongly support that the timing for referring these children to a transplant center and/or deciding to list them on the waiting list is currently too late and should be anticipated to what it is currently. This paradigm shift in the intention-to-transplant children is likely necessary for giving a better chance to an increased number of children and impacts positively on the general outcome. Networking and defining new tools for a rapid recognition of the infants who need early transplantation are necessary; centralization of these children may be helpful to achieve better outcomes than currently observed.

Prognostic markers at adolescence in patients requiring liver transplantation for biliary atresia in adulthood

BACKGROUND & AIMS

In patients with biliary atresia (BA), the rate of native liver survival (NLS) to adulthood has been reported as 14-44% worldwide. Complications related to portal hypertension (PHT) and cholangitis are common in adulthood. For those requiring liver transplantation (LT), the timing can be challenging. The aim of this study was to identify variables that could predict whether young people with BA would require LT when they are >16 years of age.

METHODS

This study was a single-centre retrospective analysis of 397 patients who underwent Kasai portoenterostomy (KP) between 1980-96 in the UK. After KP, 111/397 (28%) demonstrated NLS until 16 years of age. At final follow-up, 67 showed NLS when >16 years old (Group 1) and 22 required LT when >16 years old (Group 2). Laboratory, clinical and radiological parameters were collected for both groups at a median age of 16.06 years (13.6-17.4 years).

RESULTS

The need for LT when >16 years old was associated with higher total bilirubin (hazard ratio 1.03, p = 0.019) and lower creatinine (hazard ratio 0.95, p = 0.040), at 16 years, on multivariate analysis. Receiver-operating characteristic curve analysis demonstrated that a total bilirubin level of ≥21 µmol/L at 16 years old (AUROC = 0.848) predicted the need for LT when >16 years old, with 85% sensitivity and 74% specificity. Cholangitis episode(s) during adolescence were associated with a 5-fold increased risk of needing LT when >16 years old. The presence of PHT or gastro-oesophageal varices in patients <16 years old was associated with a 7-fold and 8.6-fold increase in the risk of needing LT, respectively.

CONCLUSIONS

BA in adulthood requires specialised management. Adult liver disease scoring models are not appropriate for this cohort. Bilirubin ≥21 µmol/L, PHT or gastro-oesophageal varices at 16 years, and cholangitis in adolescence, can predict the need for future LT in young people with BA. Low creatinine at 16 years also has potential prognostic value.

LAY SUMMARY

Patients with biliary atresia commonly require liver transplantation before reaching adulthood. Those who reach adulthood with their own liver are still at risk of needing a transplant. This study aimed to identify tests that could help clinicians predict which patients with biliary atresia who reach the age of 16 without a transplant will require one in later life. The study found that the presence of bilirubin ≥21 µmol/L, lower creatinine levels, and a history of portal hypertension or gastro-oesophageal varices at 16 years, as well as cholangitis in adolescence, could predict the future likelihood of needing a liver transplant for young people with biliary atresia.

Similarities and Differences in Allocation Policies for Pediatric Liver Transplantation Across the World

OBJECTIVES

We aimed to investigate national allocation policies for pediatric liver transplantation (LT).

METHOD

A survey was prepared by the European Society for Paediatric Gastroenterology Hepatology and Nutrition Hepatology Committee in collaboration with the North American Studies of Pediatric Liver Transplantation consortium. The survey was sent to pediatric hepatologists and transplant surgeons worldwide. National data were obtained from centrally based registries.

RESULTS

Replies were obtained from 15 countries from 5 of the world continents. Overall donation rate varied between 9 and 35 per million inhabitants. The number of pediatric LTs was 4 to 9 per million inhabitants younger than 18 years for 13 of the 15 respondents. In children younger than 2 years mortality on the waiting list (WL) varied between 0 and 20%. In the same age group, there were large differences in the ratio of living donor LT to deceased donor LT and in the ratio of split liver segments to whole liver. These differences were associated with possible discrepancies in WL mortality.

CONCLUSIONS

Similarities but also differences between countries were detected. The described data may be of importance when trying to reduce WL mortality in the youngest children.

Intellectual and academic outcomes after pediatric liver transplantation: Relationship with transplant-related factors

As survival rates for pediatric liver transplant continue to increase, research attention is turning toward long-term functional consequences, with particular interest in whether medical and transplant-related factors are implicated in neurocognitive outcomes. The relative importance of different factors is unclear, due to a lack of methodological uniformity, inclusion of differing primary diagnoses, varying transplant policies, and organ availability in different jurisdictions. This cross-sectional, single-site study sought to address various methodological limitations in the literature and the paucity of studies conducted outside of North America and Western Europe by examining the intellectual and academic outcomes of Australian pediatric liver transplant recipients (N = 40). Participants displayed significantly poorer intellectual and mathematical abilities compared with the normative population. Greater time on the transplant waitlist was a significant predictor of poorer verbal intelligence, working memory, mathematical abilities, and reading but only when considering the subgroup of children with biliary atresia. These findings support reducing the time children wait for a transplant as a priority.

Outcomes of biliary atresia in the Nordic countries - a multicenter study of 158 patients during 2005-2016

BACKGROUND/PURPOSE

Biliary atresia is the most common reason for newborn cholestasis and pediatric liver transplantation. Even after normalization of serum bilirubin after portoenterostomy, most patients require liver transplantation by adulthood due to expanding fibrosis. We addressed contemporary outcomes of biliary atresia in the Nordic countries.

METHODS

Data on center and patients characteristics, diagnostic practices, surgical treatment, adjuvant medical therapy after portoenterostomy, follow-up and outcomes were collected from all the Nordic centers involved with biliary atresia care during 2005-2016.

RESULTS

Of the 154 patients, 148 underwent portoenterostomy mostly by assigned surgical teams at median age of 64 (interquartile range 37-79) days, and 95 patients (64%) normalized their serum bilirubin concentration while living with native liver. Postoperative adjuvant medical therapy, including steroids, ursodeoxycholic acid and antibiotics was given to 137 (93%) patients. Clearance of jaundice associated with young age at surgery and favorable anatomic type of biliary atresia, whereas annual center caseload >3 patients and diagnostic protocol without routine liver biopsy predicted early performance of portoenterostomy. The cumulative 5-year native liver and overall survival estimate was 53% (95% CI 45-62) and 88% (95% CI 83-94), respectively. Portoenterostomy age <65days and annual center caseload >3 patients were predictive for long-term native liver survival, while normalization of serum bilirubin after portoenterostomy was the major predictor of both native liver and overall 5-year survival.

CONCLUSIONS

The outcomes of biliary atresia in the Nordic countries compared well with previous European studies. Further improvement should be pursued by active measures to reduce patient age at portoenterostomy.

RETROSPECTIVE PROGNOSIS STUDY

Level II.

Wait-list mortality of young patients with Biliary atresia: Competing risk analysis of a eurotransplant registry-based cohort

Liver transplantation (LT) is the standard treatment for biliary atresia (BA) patients with end-stage liver disease. The prognosis after LT has steadily improved, but overall prognosis of BA patients is also determined by mortality before LT. We aimed to quantify mortality in young BA patients on the Eurotransplant waiting list and to determine the effect of disease severity and age at time of listing on pretransplant mortality. We used a cohort study design, which incorporated data from the Eurotransplant registry. Participants were 711 BA patients who were below 5 years of age from 5 countries and listed for LT between 2001 and 2014. We applied a competing risk analysis to evaluate simultaneously the outcomes death, LT, and still waiting for a suitable organ. We used Cox proportional hazards regression to assess 2-year mortality. In a subcohort of 416 children, we performed multivariate analyses between 2-year mortality and disease severity or age, each at listing. Disease severity at listing was quantified by the Model for End-Stage Liver Disease (MELD) score, which assesses bilirubin, creatinine, albumin, and international normalized ratio as continuous variables. Two-year wait-list mortality was 7.9%. Age below 6 months and MELD score above 20 points, each at listing, were strongly and independently associated with 2-year mortality (each P < 0.001). A total of 21% of infants who fulfilled both criteria did not survive the first 6 months on the waiting list. In conclusion, our findings quantify mortality among young BA patients on the waiting list and the relative importance of risk factors (age and severity of disease at listing). Our results provide both an evidence base to rationally address high mortality in subgroups and a methodology to assess effects of implemented changes, for example, in allocation rules. Liver Transplantation 24 810-819 2018 AASLD.

Treatment Policy and Liver Histopathology Predict Biliary Atresia Outcomes: Results after National Centralization and Protocol Biopsies

BACKGROUND

Different treatment policies can influence biliary atresia outcomes, but the pathophysiology of expanding fibrosis occurring even after successful portoenterostomy remains unclear.

STUDY DESIGN

Clearance of jaundice (COJ) (bilirubin <20 μmol/L), native liver survival, and overall survival rates of biliary atresia patients were analyzed before and after national centralization of management, as well as in relation to native liver histopathology of protocol biopsies.

RESULTS

Of the 59 patients, 35 were managed after centralization and received standardized postoperative adjuvant therapy, including corticosteroids. After centralization, age at portoenterostomy decreased from 73 days to 54 days (p = 0.014) and COJ rate increased from 42% to 80% (p = 0.005), 5-year native liver survival increased from 38% to 70% (p = 0.014), and 5-year overall survival increased from 68% to 94% (p = 0.007). High-grade portal inflammation at portoenterostomy predicted COJ (odds ratio 3.66; p = 0.011) and slower fibrosis progression (β = -0.74; p = 0.005). Native liver survival was extended in patients with high-grade portal inflammation (p = 0.002) and in patients whose bilirubin normalized within 3 months (p < 0.001). Portal inflammation and cholestasis reduced only after COJ (p < 0.001), and persisting ductal reaction, reflected by cytokeratin 7-positive proliferating bile ductules and periportal hepatocytes, correlated with follow-up fibrosis (r = 0.454 to 0.763; p < 0.001 to 0.003). Cytokeratin 7 immunopositivity of periportal hepatocytes increased after COJ (p = 0.015) and was the only predictor of follow-up liver fibrosis (β = 0.36; p = 0.002) in multiple regression.

CONCLUSIONS

Biliary atresia outcomes improved significantly after centralization and standardized management. Resolution of cholestasis and reduction of high-grade portal inflammation postoperatively predict slower fibrosis progression and improved native liver survival, and persisting ductal reaction parallels progressive native liver fibrosis despite COJ.