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

Abstract

Background: 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.

Methods: 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).

Results: 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).

Conclusions: 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.

Keywords: children; lung allocation score; lung transplantation; outcomes; pediatric.

Figure 1

(A) Mean lung allocation scores at listing and (B) median waiting times for adults, adolescents and children listed for lung transplantation, by year of candidate listing. Dashed line represents year of implementation lung allocation score (LAS).

Figure 2

(A) Proportion of listed candidates reaching transplantation before and after LAS implementation, by candidate age group.(B) Annual transplant rate (mean annual transplants per 100 patient-years on waitlist) by year of listing and candidate age group. Dashed line represents year of implementation of lung allocation score (LAS).

Figure 3

(A) Proportion of waitlist deaths before and after LAS implementation, by candidate age group. (B) Annual waitlist mortality rate (mean annual waitlist deaths per 100 patient-years on waitlist) by year of listing and candidate age group. Waitlist death included waitlist removals for both death and “too sick to transplant.” Dashed line represents year of implementation of lung allocation score (LAS).

Figure 4

Kaplan–Meier analysis of post-transplant survival for (A) adults, (B) adolescents and (C) children listed before or after LAS implementation. (D) Comparison of post-transplant survival for adults, adolescents and children listed after implementation of the lung allocation score (LAS).