Pediatric Transplant Candidates Research Articles

Changes in offer and acceptance patterns for pediatric kidney transplant candidates under the new Kidney Allocation System.

Stakeholders have expressed concerns regarding decreased deceased donor kidney transplant (DDKT) rates for pediatric candidates under the Kidney Allocation System (KAS). To better understand what might be driving this, we studied Scientific Registry of Transplant Recipients kidney offer data for 3642 pediatric (age <18 years) kidney-only transplant candidates between December 31, 2012 to December 3, 2014 (pre-KAS) and December 4, 2014 to January 6, 2017 (post-KAS). We used negative binomial regression and multilevel logistic regression to compare offer and acceptance rates pre- and post-KAS. We stratified by donor age (<18, 18-34, and 35+ years) and KDPI (<35% and ≥35%) to reflect differing allocation prioritization pre-KAS and post-KAS. As might be expected from prioritization changes, post-KAS candidates were less likely to receive offers for donors 18-34years old with KDPI≥35% (adjusted incidence rate ratio [aIRR]: 0.18 0.210.25 , P<.001), and more likely to receive offers for donors 18-34years old and KDPI<35% (aIRR: 1.12 1.201.29 , P<.001). However, offer acceptance practices also changed post-KAS: kidneys from donors 18-34years old and KDPI<35% were 23% less likely to be accepted post-KAS (adjusted odds ratio: 0.61 0.770.98 , P=.03). Using kidneys from donors 18-34years old with KDPI<35% post-KAS to the same extent they were used pre-KAS might be an effective strategy to mitigate any decrease in DDKT rates for pediatric candidates.

Ureterostomy as an alternative to ileal conduits in pediatric kidney transplantation.

Urinary diversion in pediatric renal transplant candidates with bladders not amenable to primary reconstruction can be achieved by pre-transplant ileal conduit creation. We performed cutaneous ureterostomies to limit pre-transplant surgery, protect the peritoneum for dialysis, transplant patients sooner, and preserve ureter length for future surgical reconstruction. We compared four pediatric transplant recipients with ureterostomies to four recipients with ileal conduits from 2009 to 2017. All patients with ileal conduits developed at least one urinary tract infection (UTI) within 1year of transplant and three of four patients had recurrent UTIs within the first year. Two patients required ileal conduit revisions for redundant conduits and recurrent UTIs. Of the four ureterostomy patients, two patients had UTIs within one year of transplant. Two patients developed ureterostomy strictures requiring revision at the fascial level; one was associated with a UTI. In our small case series, ureterostomy allowed for a single operative intervention with preservation of ureter length for later reconstruction. Ureterostomy is safe and recurrent UTI may be lower in the ureterostomy group. Long-term evaluation of ureterostomy for urinary diversion in pediatric kidney transplant is warranted.

Management of pediatric cardiac transplantation candidates with pulmonary hypertension and high pulmonary vascular resistance.

Right ventricular failure is an important cause of mortality and morbidity after orthotopic heart transplantation (OHT). The right ventricle of the donor may fail to accommodate to the high pulmonary vascular resistance (PVR) of the recipient. Pulmonary hypertension (PH) due to chronic heart failure with PVRi > 4 Wood units.m2, transpulmonary gradient > 15 mmHg adversely affect the outcome of OHT. In this study we aimed to evaluate management strategies in our pediatric cardiac transplantation candidates with PH and high PVR prior to OHT. Twenty-six cardiac transplantation candidates (age: 10.2 ± 4.6, 1-17 years) underwent cardiac catheterization for the determination of PVR and pulmonary arterial pressure. They were admitted to the hospital and received 1-3 days of intravenous (IV) vasodilator therapy; 0.5-3 μg/kg/min nitroglyserin and/or 0.5-3 μg/kg/min nitroprusside, 5-15 μg/kg/min dobutamin and/or dopamin to keep systolic blood pressure above 80 mmHg. Thirteen patients had dilated cardiomyopathy (CMP), 11 had restrictive CMP, one had hypertrophic CMP and one had congenital heart disease (CHD). Nineteen of the 26 patients underwent OHT. Mean pulmonary arterial pressure of the patients ranged between 11 and 82 mmHg (30.4 ± 16 mmHg) and PVRi between 0.41-21.4 Wood units.m2 (5.3 ± 5.7). Nine patients had PVRi above 4 Wood units.m < sup > 2 < /sup > . Six of these patients had IV treatment for longer than three days and some received specific anti-PH treatment. Eventually they underwent a pulmonary vasoreactivity test with IV iloprost and six had PVRi < 4 Wood units.m < sup > 2 < /sup > . Five of them underwent OHT. Cardiac transplantation candidates with PH and high PVR should be evaluated after conditioning with vasodilator and inotropic treatment. Specific treatment for PH and vasoreactivity testing may help selected patients reenter the transplantation list.

Underimmunization of the solid organ transplant population: An urgent problem with potential digital health solutions.

Solid organ transplant recipients are at risk for potentially life-threatening infections due to lifelong immunosuppression. Vaccine-preventable infections result in graft injury, morbidity, mortality, and significantly increased medical costs. Unfortunately, the majority of transplant recipients continue to be underimmunized at the time of transplant and thereafter. Given the rising rates of vaccine hesitancy and refusal in the general population, transplant recipients can no longer rely on herd immunity to protect them from vaccine-preventable infections. Novel tools are desperately needed to overcome transplant-specific immunization barriers to improve immunization rates in this high-risk population. Digital health technologies may offer a solution by addressing transplant-specific barriers: specifically, providing accurate information about vaccine safety, efficacy, and timing in the pre- and posttransplant periods; making a complete immunization record universally available and easily accessible; enabling communication between patients and multiple providers; and providing automated vaccine reminders to both patients and providers when vaccines are due using transplant-specific immunization guidelines. Digital health has transformed health care by empowering patients with their own health information and connecting patients, their providers, and public health officials. In doing so, it offers a potential platform to address and overcome the problem of underimmunization in the transplant population.

Management of the sensitized pediatric heart transplant patient.

Despite advancements in transplant immunosuppression and techniques for managing critically ill patients awaiting heart transplantation, children who are immunologically sensitized to human leukocyte antigen remain at increased risk for morbidity and mortality, both while awaiting and after heart transplant. In this review we will discuss the epidemiology of sensitization, review the immunologic basis and methods of human leukocyte antigen antibody detection, describe outcomes for sensitized pediatric transplant candidates, and consider both pre- and post-transplant management options for sensitized patients.

Time for evidence-based, standardized donor size matching for pediatric heart transplantation

BackgroundAccurately predicting cardiac size by other body parameters has long been problematic to determine whether a donor heart will serve a given waitlist candidate, yet hundreds of heart donors are turned down annually for size mismatch. ObjectivesWe sought to describe how donor body weight parameters are currently utilized in cardiac transplantation and its influence on waitlist outcomes. MethodsFrom the United Network for Organ Sharing database, pediatric (age <18 years) heart transplant candidates were divided into lower quartile, interquartile, and upper quartile categories based on final maximum acceptable donor–candidate weight ratio (DCW), expressed as percentage. Baseline characteristics and waitlist outcomes, including monthly offers/candidate and survival were compared. ResultsOverall median DCW was 200% (range, 159%-241%). Patients with congenital heart disease had higher DCW than those with cardiomyopathy (223% vs 203%; P < .001). Number of monthly offers/candidate (5.0, 5.6, and 7.2, respectively; P < .001) increased with quartile of DCW. Posttransplant survival was similar amongst the groups (log-rank P > .05). Subgroup analysis of critically ill children showed a waitlist survival advantage in those listed with a DCW ≥200% (P < .001). ConclusionsDespite substantial practice variation in acceptable donor weight in pediatric heart transplantation, patients listed with variable DCW had similar posttransplant survival. However, in critically ill patients, higher DCW was associated with greater waitlist survival. Better understanding of the importance of donor weight could reduce practice variability and improve organ use and waitlist outcomes for pediatric cardiac transplant candidates.

P2.41: Gastrointestinal outcomes of gastroschisis in and around Osaka, Japan

Introduction: According to the Intestinal Transplant Registry report 2018, gastroschisis was the most frequent indication (21%) for pediatric intestinal transplantation. However, in Japan, none of the pediatric intestinal transplant candidates has gastroschisis. The purpose of this study was to analyze gastrointestinal outcomes of gastroschisis in and around Osaka, Japan. Methods: One hundred and nine patients with gastroschisis were treated between January 1982 and December 2018 at our three hospitals. The patients’ gender, gestational age at birth, birth weight, Apgar Score, delivery route, fetal diagnosis, gastrointestinal complications of gastroschisis, surgical treatment, and outcomes were analyzed. Results: Mean gestational age at birth of the 109 patients (males: 57, 52%) was 36.3 ± 2.1 weeks. Mean birth weight was 2159 ± 441 g, mean Apgar Score (after 1 minute / after 5 minute) was 6.9 ± 2.3 / 8.4 ± 1.2, and 38 patients were delivered by Cesarean section. Fetal diagnosis of gastroschisis was made in 78 (72%) cases. All 109 patients were operated for gastroschisis, with primary repair in 63, silo repair in 23, and silo placement with delayed abdominal closure in 23. Eight patients (7%) had the gastrointestinal complications: seven had atresia of the intestine or colon, one had intestinal perforation. Closed gastroschisis was detected in three patients after birth. The patients with gastrointestinal complications were treated concurrently by intestinal anastomosis or enterostomy at the initial operation. Three of the eight patients underwent massive intestinal resection, resulting in short bowel syndrome (SBS), and required total parenteral nutrition (TPN) for about a year. Two of the three patients with SBS survived weaning off TPN. However, the other baby with SBS died of intestinal failure-associated liver disease. The other two patients without gastrointestinal complications died, one was an extremely low birth weight infant and the other with thrombosis in the lower extremities. Eventually, the remaining 106 (97.2 %) patients with gastroschisis have been surviving without TPN. Conclusion: Gastrointestinal complications are rare in Japanese patients with gastroschisis. One of the factors contributing to this might be the low incidence of closed gastroschisis and low prevalence of SBS and complications secondary to intestinal failure after repair of gastroschisis. Ethical approval: The hospital research ethics committee (reference number H30-36).

A donor risk index for graft loss in pediatric living donor kidney transplantation.

Pediatric kidney transplant candidates often have multiple potential living donors (LDs); no evidence-based tool exists to compare potential LDs, or to decide between marginal LDs and deceased donor (DD) kidney transplantation (KT). We developed a pediatric living kidney donor profile index (P-LKDPI) on the same scale as the DD KDPI by using Cox regression to model the risk of all-cause graft loss as a function of living donor characteristics and DD KDPI. HLA-B mismatch (adjusted hazard ratio [aHR] per mismatch=1.04 1.271.55 ), HLA-DR mismatch (aHR per mismatch=1.02 1.231.49 ), ABO incompatibility (aHR=1.20 3.268.81 ), donor systolic blood pressure (aHR per 10mm Hg=1.01 1.071.18 ), and donor estimated GFR (eGFR; aHR per 10mL/min/1.73m2 = 0.88 0.940.99 ) were associated with graft loss after LDKT. Median (interquartile range [IQR]) P-LKDPI was -25 (-56 to 12). 68% of donors had P-LKDPI <0 (less risk than any DD kidney) and 25% of donors had P-LKDPI >14 (more risk than median DD kidney among pediatric KT recipients during the study period). Strata of LDKT recipients of kidneys with higher P-LKDPI had a higher cumulative incidence of graft loss (39% at 10years for P-LDKPI ≥20, 28% for 20>P-LKDPI ≥-20, 23% for -20>P-LKDPI ≥-60, 19% for P-LKDPI <-60 [log rank P<.001]). The P-LKDPI can aid in organ selection for pediatric KT recipients by allowing comparison of potential LD and DD kidneys.

Development and Validation of a Pediatric Heart Failure Risk-Prediction Model for Children Listed for Heart Transplantion in the Current Era

Purpose Previous studies have developed validated risk-prediction models for pediatric heart failure (HF). However, ventricular assist device (VAD) use and organ allocation practices have shifted markedly over the last decade for pediatric heart transplant (HT) candidates. We sought to develop and validate a risk-prediction model in a contemporary cohort of pediatric HF patients. Methods Children Results The selected predictive model had 5 categorical variables: mechanical support [ECMO (Odds ratio, OR 6.3), VAD support (OR 1.3), vs no support], ventilator support (OR 2.5), cardiac diagnosis [congenital heart disease (CHD) (OR 2.3), vs. cardiomyopathy], renal dysfunction [dysfunction (OR 2.3), vs. normal], and weight categories at listing [25-50 kg (OR 2.0), 10-25 kg (OR 3.2), 5-10 kg (OR 3.7), and 0-5 kg (OR 5.6), vs. ≥50 kg]. The final model developed using the derivation cohort after internal cross-validation (N=2029; C-statistic 0.83, Hosmer-Lemeshow Goodness of Fit P=0.81) performed well in the independent validation cohort (N=1194, C-statistic 0.81, HL P=0.68), suggesting excellent prediction in a contemporary cohort of pediatric HF patients as shown in the calibration plot in Figure 1. Conclusion This heart failure risk-prediction model using 5 baseline clinical factors at the time of listing has excellent prediction characteristics for 30-day mortality in a contemporary cohort of children. The model may be useful to support decision-making surrounding referral for advanced cardiac therapies including HT and VAD support.

Infections among pediatric transplant candidates: An approach to decision-making.

The presence of infections in the immediate pretransplant period poses challenges in decision-making. Delaying transplantation because of these infections may be required, but is associated with a risk to the potential recipient. The aim of this project was to develop a structured framework based on expert opinion to guide decision-making regarding the safety of transplantation for candidates with infection immediately before transplant, and to show how this framework can be applied to clinical scenarios. Categories were created as follows: Category A: no delay; Category B: brief delay (≤1week); Category C: intermediate delay (>1week); and Category D: more prolonged or indefinite delay. A survey containing 59 clinical scenarios was sent to members of the IPTA ID CARE committee. Answers were reviewed, and the level of agreement was characterized as follows: Level 1: ≥75% agreement; Level 2:51%-74% agreement; and Level 3: ≤50% agreement. 95% CIs were calculated for the mean overall agreement across 59 scenarios. Among the panel, the agreement level ranged from 33% to 92% with the mean overall agreement across the 59 scenarios being 61%. For 7/59 scenarios, the lower bound of 95% CI was greater than 50%, indicating a difference at the 5% level of significance between the observed proportion and the chance level of 0.5. The document provides expert opinion regarding the need to delay transplantation in the setting of different infections. The most important points in the decision to proceed to SOT included the urgency of transplantation and the severity of infection.

1.11 Provider Perspectives on Substance Use Among Adolescent Solid Organ Transplant Patients

Substance use may pose adverse health issues after transplant surgery; however, policies related to substance use among pediatric transplant candidates remain inconsistent. In this study, transplant providers’ perspectives on substance use were surveyed to develop guidelines and treatment recommendations for substance use among pediatric transplant candidates.

Fairness, severe intellectual disability, and the special case of transplantation.

Children with severe intellectual disability have historically been excluded from solid organ transplantation. The purpose of this article was to review the arguments for excluding this population, including claims of poorer recipient and graft survival, a lower QoL as pediatric recipients become adults, and poorer outcomes for other, more deserving pediatric transplant candidates, and make the case that these arguments are no longer persuasive. We will argue that pediatric transplant centers for reasons of social justice, value of relationships, power differential, and fairness should generally not consider intellectual ability or disability as a criterion when making decisions regarding organ transplant eligibility.

Vaccinations in pediatric kidney transplant recipients.

Pediatric kidney transplant (KT) candidates should be fully immunized according to routine childhood schedules using age-appropriate guidelines. Unfortunately, vaccination rates in KT candidates remain suboptimal. With the exception of influenza vaccine, vaccination after transplantation should be delayed 3-6months to maximize immunogenicity. While most vaccinations in the KT recipient are administered by primary care physicians, there are specific schedule alterations in the cases of influenza, hepatitis B, pneumococcal, and meningococcal vaccinations; consequently, these vaccines are usually administered by transplant physicians. This article will focus on those deviations from the normal vaccine schedule important in the care of pediatric KT recipients. The article will also review human papillomavirus vaccine due to its special importance in cancer prevention. Live vaccines are generally contraindicated in KT recipients. However, we present a brief review of live vaccines in organ transplant recipients, as there is evidence that certain live virus vaccines may be safe and effective in select groups. Lastly, we review vaccination of pediatric KT recipients prior to international travel.

Durability of the hepatitis B vaccination in pediatric renal transplant recipients.

Since hepatitis B virus (HBV) vaccine implementation, HBV infection has significantly decreased. However, adult renal transplant recipients show a higher rate of seroreversion compared to the general population, leading to HBV infection risk. Data are limited in pediatric renal transplant recipients. Retrospective data were collected to determine the seroprotection and durability of HBV vaccination in pediatric renal transplant patients from 2004 to 2014. One hundred subjects were categorized based on pre- and post-transplant hepatitis B surface antibody (HBsAb). Pretransplant, 85 recipients (85%) had a positive HBsAb compared to 15 (15%) with negative HBsAb. In univariable analyses, other than age (P<.05) no significant differences existed pretransplant by demographics, pretransplantation dialysis, or number of vaccinations. Of the 85 pretransplantation responders, 53 (62%) remained HBsAb positive post-transplantation, 28 (32%) seroreverted, and 4 developed indeterminate titers. All seroreversions occurred within 5years post-transplant. Receipt of a living donor organ had higher risk of reversion (P =.005). No significant differences were found in demographics, pretransplantation dialysis, vaccination number, or acute rejection. Despite vaccination, 15% of pediatric renal transplant candidates were seronegative, and an additional 32% lost seroprotection within 5years post-transplantation leaving nearly half of transplant recipients at risk for HBV infection.

Organ allocation and utilization in pediatric transplantation

Pediatric transplant candidates include heart, lung, liver, pancreas, small intestine, and kidney. The purpose of this article is to review the history and current methods for determining priority of the above-mentioned transplantable organs. The methods used by the authors involved the review of historical and current manuscripts and UNOS policy documents. We summarized the findings in order to create a concise review of the current policies and wait times for transplantation in pediatric transplant patients.

Impact of a pharmacist-led vaccine recommendation program for pediatric kidney transplant candidates.

Pediatric transplant recipients commonly have deficient vaccination status at the time of transplantation. Utilizing transplant pharmacists to improve vaccination rates has not previously been described. This single-center, retrospective study evaluated the impact of transplant pharmacist interventions on the completion rate of vaccination schedules at time of kidney transplant. Patients who received pharmacist-led vaccination recommendations prior to transplant were compared to patients without pharmacist recommendations. Forty-seven pediatric patients were included: 24 intervention patients and 23 control patients. The median percentage of up-to-date vaccinations at time of transplant was significantly higher in intervention group (91%; IQR 86%-100%) vs. control group (80%; IQR 71%-80%) (P<.0001). The median change in up-to-date vaccinations from time of evaluation to time of transplant was also significantly higher in the intervention group (7.5%) compared to the control group (0%) (P<.0001). There was no difference in live vaccination rates. No patients in either group were readmitted for a vaccine-preventable disease within 6months post-transplant. With pharmacist intervention, significantly more patients were up to date with vaccination schedules at the time of transplant. These results suggest that a transplant pharmacist may serve as a valuable resource to increase vaccination schedule compliance between time of evaluation and transplantation.

Inferior Outcomes on the Waiting List in Low-Volume Pediatric Heart Transplant Centers.

Low case volume has been associated with poor outcomes in a wide spectrum of procedures. Our objective was to study the association of low case volume and worse outcomes in pediatric heart transplant centers, taking the novel approach of including waitlist outcomes in the analysis. We studied a cohort of 6482 candidates listed in the Organ Procurement and Transplantation Network for pediatric heart transplantation between 2002 and 2014; 4665 (72%) of the candidates underwent transplantation. Candidates were divided into groups according to the average annual transplantation volume of the listing center during the study period: more than 10, six to 10, three to five, or fewer than three transplantations. We used multivariate Cox regression analysis to identify independent risk factors for waitlist and posttransplantation mortality. Of the 6482 candidates, 24% were listed in low-volume centers (fewer than three annual transplantations). Of these listed candidates in low-volume centers, only 36% received a transplant versus 89% in high-volume centers (more than 10 annual transplantations) (p < 0.001). Listing at a low-volume center was the most significant risk factor for waitlist death (hazard ratio [HR] 4.5, 95% confidence interval [CI] 3.5-5.7 in multivariate Cox regression and HR 5.6, CI 4.4-7.3 in multivariate competing risk regression) and was significant for posttransplantation death (HR 1.27, 95% CI 1.0-1.6 in multivariate Cox regression). During the study period, one-fourth of pediatric transplant candidates were listed in low-volume transplant centers. These children had a limited transplantation rate and a much greater risk of dying while on the waitlist.

Management of post-transplant lymphoproliferative disorders.

Post-transplant lymphoproliferative disease (PTLD) is a major complication of hematopoietic stem cell and solid organ transplantation. The incidence of transplantation in childhood has been steadily rising, making PTLD the most common form of lymphoproliferation in childhood. The purpose of this review is to summarize the role of the Epstein-Barr virus (EBV) in the pathophysiology and discuss the management of PTLD. More than 90% of pediatric PTLD is EBV-positive. In immunocompetent hosts, the virus is controlled by cytotoxic T-cells, the cells targeted by immunosuppression to avoid graft-versus-host disease and/or organ rejection in transplant patients. The majority of pediatric transplant candidates are EBV-negative prior to transplant increasing the risk of EBV-induced lymphoproliferation upon seroconversion after transplant. Treatment options include reduction of immunosuppression, anti-CD20 monoclonal antibodies, and/or chemotherapy. Advanced understanding of the importance of cellular immunity in controlling lymphoproliferation has led to the development of cellular therapies targeting virus-specific antigens. PTLD is the most common form of lymphoproliferation in childhood due to the rising incidence of transplantation. EBV plays a pivotal role in the pathophysiology. Cellular therapies targeting viral antigens may replace chemotherapy in the treatment of PTLD in the near future.

Poor outcomes for children on the wait list at low-volume kidney transplant centers in the United States.

Low case volume has been associated with worse survival outcomes in solid organ transplantation. Our aim was to analyze wait-list outcomes in conjunction with posttransplant outcomes. We studied a cohort of 11,488 candidates waitlisted in the Organ Procurement and Transplantation Network (OPTN) for pediatric kidney transplant between 2002 and 2014, including both deceased- and living-donor transplants; 8757 (76%) candidates received a transplant. Candidates were divided into four groups according to the average volume of yearly transplants performed in the listing center over a 12-year period: more than ten, six to nine, three to five, and fewer than three. We used multivariate Cox regression analysis to identify independent risk factors for wait list and posttransplant mortality. Twenty-seven percent of candidates were listed at low-volume centers in which fewer than three transplants were performed annually. These candidates had a limited transplant rate; only 49% received a transplant versus 88% in high-volume centers (more than ten transplants annually) (p < 0.001). Being listed at a low-volume center showed a fourfold increased risk for death while on the wait list [hazard ratio (HR) 4.0 in multivariate Cox regression and 6.1 in multivariate competing risk regression]. It was not a significant risk factor for posttransplant death in multivariate Cox regression. Pediatric transplant candidates are listed at low-volume transplant centers are transplanted less frequently and have a much greater risk of dying while on the wait list. Further studies are needed to elucidate the reasons behind the significant outcome differences.

Improved waitlist and transplant outcomes for pediatric lung transplantation after implementation of the lung allocation score

Although the lung allocation score (LAS) has not been considered valid for lung allocation to children, several additional policy changes for pediatric lung allocation have been adopted since its implementation. We compared changes in waitlist and transplant outcomes for pediatric and adult lung transplant candidates since LAS implementation. The United Network for Organ Sharing database was reviewed for all lung transplant listings during the period 1995 to June 2014. Outcomes were analyzed based on date of listing (pre-LAS vs post-LAS) and candidate age at listing (adults >18 years, adolescents 12 to 17 years, children 0 to 11 years). Of the 39,962 total listings, 2,096 (5%) were for pediatric candidates. Median waiting time decreased after LAS implementation for all age groups (adults: 379 vs 83 days; adolescents: 414 vs 104 days; children: 211 vs 109 days; p < 0.001). The proportion of candidates reaching transplant increased after LAS (adults: 52.6% vs 71.6%, p < 0.001; adolescents: 40.3% vs 61.6%, p < 0.001; children: 42.4% vs 50.9%, p = 0.014), whereas deaths on the waitlist decreased (adults: 28.0% vs 14.4%, p < 0.001; adolescents: 33.1% vs 20.9%, p < 0.001; children: 32.2% vs 25.0%; p = 0.025), despite more critically ill candidates in all groups. Median recipient survival increased after LAS for adults and children (adults: 5.1 vs 5.5 years, p < 0.001; children: 6.5 vs 7.6 years, p = 0.047), but not for adolescents (3.6 vs 4.3 years, p = 0.295). Improvements in waiting time, mortality and post-transplant survival have occurred in children after LAS implementation. Continued refinement of urgency-based allocation to children and broader sharing of pediatric donor lungs may help to maximize these benefits.