Pediatric End-stage Liver Disease Scores as a Method of Assessing Mortality Risk or Prioritization to Transplantability: Let Us Save the Children

Estimating risk of prolonged mechanical ventilation after liver transplantation in children: PROVE-ALT score

BACKGROUND

Children at high risk for prolonged mechanical ventilation (PMV) after liver transplantation (LT) need to be identified early to optimize pulmonary support, allocate resources, and improve surgical outcomes. We aimed to develop and validate a metric that can estimate risk for Prolonged Ventilation After LT (PROVE-ALT).

METHODS

We identified preoperative risk factors for PMV by univariable analysis in a retrospective cohort of pediatric LT recipients between 2011 and 2017 (n = 205; derivation cohort). We created the PROVE-ALT score by mapping multivariable logistic regression coefficients as integers, with cutoff values using the Youden Index. We validated the score by C-statistic in a retrospectively collected separate cohort of pediatric LT recipients between 2018 and 2021 (n = 133, validation cohort).

RESULTS

Among total 338 patients, 21% (n = 72) were infants; 49% (n = 167) had cirrhosis; 8% (n = 27) required continuous renal replacement therapy (CRRT); and 32% (n = 111) required management in hospital (MIH) before LT. Incidence of PMV post-LT was 20% (n = 69) and 3% (n = 12) required tracheostomy. Independent risk factors (OR [95% CI]) for PMV were cirrhosis (3.8 [1-14], p = .04); age <1-year (8.2 [2-30], p = .001); need for preoperative CRRT (6.3 [1.2-32], p = .02); and MIH before LT (12.4 [2.1-71], p = .004). PROVE-ALT score ≥8 [Range = 0-21] accurately predicted PMV in the validation cohort with 73% sensitivity and 80% specificity (AUC: 0.81; 95% CI: 0.71-0.91).

CONCLUSION

PROVE-ALT can predict PMV after pediatric LT with a high degree of sensitivity and specificity. Once externally validated in other centers, PROVE-ALT will empower clinicians to plan patient-specific ventilation strategies, provide parental anticipatory guidance, and optimize hospital resources.

Effect of remote ischemic preconditioning among donors and recipients following pediatric liver transplantation: A randomized clinical trial

BACKGROUND

Studies suggested that remote ischemic preconditioning (RIPC) may effectively lessen the harmful effects of ischemia reperfusion injury during organ transplantation surgery.

AIM

To investigate the protective effects of RIPC on living liver donors and recipients following pediatric liver transplantation.

METHODS

From January 2016 to January 2019 at Renji Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, 208 donors were recruited and randomly assigned to four groups: S-RIPC group (no intervention; n = 55), D-RIPC group (donors received RIPC; n = 51), R-RIPC group (recipients received RIPC, n = 51) and DR-RIPC group (both donors and recipients received RIPC; n = 51). We primarily evaluated postoperative liver function among donors and recipients and incidences of early allograft dysfunction, primary nonfunction and postoperative complications among recipients.

RESULTS

RIPC did not significantly improve alanine transaminase and aspartate aminotransferase levels among donors and recipients or decrease the incidences of early allograft dysfunction, primary nonfunction, and postoperative complications among recipients. Limited protective effects were observed, including a lower creatinine level in the D-RIPC group than in the S-RIPC group on postoperative day 0 (P < 0.05). However, no significant improvements were found in donors who received RIPC. Furthermore, RIPC had no effects on the overall survival of recipients.

CONCLUSION

The protective effects of RIPC were limited for recipients who received living liver transplantation, and no significant improvement of the prognosis was observed in recipients.

Natural Course of Pediatric Portal Hypertension

The etiology of portal hypertension (pHTN) in children differs from that of adults and may require different management strategies. We set out to review the etiology, management, and natural history of pHTN at a pediatric liver center. From 2008 to 2018, 151 children and adolescents with pHTN were identified at a free‐standing children’s hospital. Patients were stratified by etiology of pHTN (intrahepatic disease [IH], defined as cholestatic disease and fibrotic or hepatocellular disease; extrahepatic disease [EH], defined as hepatic vein obstruction and prehepatic pHTN). Patients with EH were more likely to undergo an esophagoduodenscopy for a suspected gastrointestinal bleed (77% vs. 41%; P < 0.01). Surgical interventions differed based on etiology (P < 0.01), with IH more likely resulting in a transplant only (65%) and EH more likely to result in a shunt only (43%); 30% of patients with IH and 47% of patients with EH did not undergo an intervention for pHTN. Kaplan‐Meier analysis revealed a significant increase in mortality in the group that received no intervention compared to shunt, transplant, or both and lower mortality in patients with prehepatic pHTN compared to other etiologies (P < 0.01 each). Multivariate analysis revealed increased odds of mortality in patients with refractory ascites (odds ratio [OR], 4.34; 95% confidence interval [CI], 1.00, 18.88; P = 0.05) and growth failure (OR, 13.49; 95% CI, 3.07, 58.99; P < 0.01). Conclusion: In this single institution study, patients with prehepatic pHTN had better survival and those who received no intervention had higher mortality than those who received an intervention. Early referral to specialized centers with experience managing these complex disease processes may allow for improved risk stratification and early intervention to improve outcomes.

Split liver transplantation is utilized infrequently and concentrated at few transplant centers in the United States

Split liver transplantation (SLT) is 1 strategy for maximizing the number of deceased donor liver transplants. Recent reports suggest that utilization of SLT in the United States remains low. We examined deceased donor offers that were ultimately split between 2010 and 2014. SLTs were categorized as "primary" and "secondary" transplants. We analyzed allocation patterns and used logistic regression to evaluate factors associated with secondary split discard. Four hundred eighteen livers were split: 54% from adult, 46% from pediatric donors. Of the 227 adult donor livers split, 61% met United Network for Organ Sharing "optimal" split criteria. A total of 770 recipients (418 primary and 352 secondary) were transplanted, indicating 16% discard. Ninety-two percent of the 418 primary recipients were children, and 47% were accepted on the first offer. Eighty-seven percent of the 352 secondary recipients were adults, and 7% were accepted on the first offer. Of the 352 pairs, 99% were transplanted in the same region, 36% at the same center. In logistic regression, shorter donor height was associated with secondary discard (odds ratio 0.97 per cm, 95% CI 0.94-1.00, P = .02). SLT volume by center was not predictive of secondary discard. Current policy proposals that incentivize SLT in the United States could increase the number of transplants to children and adults.

Impact of the Pediatric End-Stage Liver Disease (PELD) growth failure thresholds on mortality among pediatric liver transplant candidates

The Pediatric End-Stage Liver Disease (PELD) score is intended to determine priority for children awaiting liver transplantation. This study examines the impact of PELD's incorporation of "growth failure" as a threshold variable, defined as having weight or height <2 standard deviations below the age and gender norm (z-score <2). First, we demonstrate the "growth failure gap" created by PELD's current calculation methods, in which children have z-scores <2 but do not meet PELD's growth failure criteria and thus lose 6-7 PELD points. Second, we utilized United Network for Organ Sharing (UNOS) data to investigate the impact of this "growth failure gap." Among 3291 pediatric liver transplant candidates, 26% met PELD-defined growth failure, and 17% fell in the growth failure gap. Children in the growth failure gap had a higher risk of waitlist mortality than those without growth failure (adjusted subhazard ratio [SHR] 1.78, 95% confidence interval [95% CI] 1.05-3.02, P = .03). They also had a higher risk of posttransplant mortality (adjusted HR 1.55, 95% CI 1.03-2.32, P = .03). For children without PELD exception points (n = 1291), waitlist mortality risk nearly tripled for those in the gap (SHR 2.89, 95% CI 1.39-6.01, P = .005). Current methods for determining growth failure in PELD disadvantage candidates arbitrarily and increase their waitlist mortality risk. PELD should be revised to correct this disparity.