Pediatr Transplantation 2015: 19: 249–251
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Pediatric Transplantation DOI: 10.1111/petr.12434
Editorial
Pursuing distributive justice in pediatric lung transplantation The United Network for Organ Sharing is a nonprofit organization that has administered the Organ Procurement and Transplantation Network via contract with the US Federal Government since 1984. Despite being involved in an area of American medicine filled with potential and actual medical, legal, and ethical controversies, UNOS has largely managed to operate under the radar of public surveillance and partisan politics since its inception. A notable exception in 2013 involved the case of a dying 11-yr-old child with cystic fibrosis listed for more than a year at a pediatric lung transplant program without receiving a lung transplant (1). The focus of the family and the public discussions which followed centered on the Lung Allocation Score (LAS) by which patients aged 11 yr of age and younger are stratified for priority in the distribution for donor lungs. Ultimately, the UNOS Board of Directors accepted a modification of the LAS system, which has subsequently been integrated into policy to permit individual lung transplant candidates under 12 yr of age to be given an LAS score so as to access lungs from donors older than 11 yr of age. That exception was formally written into UNOS policies in 2014 (policy 10.2.B) (2) and requires a request to the Thoracic Review Board by the transplant program where the child is listed. In the article in this issue of the Journal by Keeshan et al. (3), the authors take a creatively different approach to the problem of distribution of lungs to young donors. In lieu of age, the authors use height as a discriminator. Unlike candidates for other solid organs, lung transplant candidates have always been listed by blood type and height. In normal individuals, height is a more accurate predictor of lung size and function compared with weight. The authors chose to divide the lung transplant candidate pool into three groups: 150 cm in height. Their analysis of data from the UNOS database 2005 through 2013 shows
some interesting but generally unsurprising results—shorter candidates are younger and have shorter six-minute walk test distance, greater likelihood of being on mechanical ventilation (and presumably in an ICU setting), and lower BMI than taller cohorts. Multivariate analysis showed that pre-transplant mortality was associated with shorter height, male gender, higher LAS, and patients on ECMO during listing. Age was not included in the analysis. The authors discuss several possible reasons that candidates of shorter stature might explain higher mortality. The first factor discussed is the association between short height and decreased functional status. There is no reference for this hypothesis and no further discussion. This reader does not consider this hypothesis convincing. Secondly, the authors suggest smaller thoracic volume might significantly restrict the donor pool from which an individual candidate would require an organ. To some extent, this size constraint would seem to apply to pediatric heart transplant candidates as well. I shall return to comparative heart data in that light subsequently. The authors suggest that the numeric restriction of the lung donor pool by UNOS rules would result in longer wait time and higher wait list mortality. Indeed, the UNOS database covering the years 1999–2004 shows a median waiting time for pediatric lung candidates 6–10 yr of age >1000 days and for similarly aged heart transplant candidates less than 100 days (4)! The authors present no other possible factors to account for the difficult challenges of the pediatric lung transplant candidate
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Pediatric Transplantation DOI: 10.1111/petr.12434
Editorial
Pursuing distributive justice in pediatric lung transplantation The United Network for Organ Sharing is a nonprofit organization that has administered the Organ Procurement and Transplantation Network via contract with the US Federal Government since 1984. Despite being involved in an area of American medicine filled with potential and actual medical, legal, and ethical controversies, UNOS has largely managed to operate under the radar of public surveillance and partisan politics since its inception. A notable exception in 2013 involved the case of a dying 11-yr-old child with cystic fibrosis listed for more than a year at a pediatric lung transplant program without receiving a lung transplant (1). The focus of the family and the public discussions which followed centered on the Lung Allocation Score (LAS) by which patients aged 11 yr of age and younger are stratified for priority in the distribution for donor lungs. Ultimately, the UNOS Board of Directors accepted a modification of the LAS system, which has subsequently been integrated into policy to permit individual lung transplant candidates under 12 yr of age to be given an LAS score so as to access lungs from donors older than 11 yr of age. That exception was formally written into UNOS policies in 2014 (policy 10.2.B) (2) and requires a request to the Thoracic Review Board by the transplant program where the child is listed. In the article in this issue of the Journal by Keeshan et al. (3), the authors take a creatively different approach to the problem of distribution of lungs to young donors. In lieu of age, the authors use height as a discriminator. Unlike candidates for other solid organs, lung transplant candidates have always been listed by blood type and height. In normal individuals, height is a more accurate predictor of lung size and function compared with weight. The authors chose to divide the lung transplant candidate pool into three groups: 150 cm in height. Their analysis of data from the UNOS database 2005 through 2013 shows
some interesting but generally unsurprising results—shorter candidates are younger and have shorter six-minute walk test distance, greater likelihood of being on mechanical ventilation (and presumably in an ICU setting), and lower BMI than taller cohorts. Multivariate analysis showed that pre-transplant mortality was associated with shorter height, male gender, higher LAS, and patients on ECMO during listing. Age was not included in the analysis. The authors discuss several possible reasons that candidates of shorter stature might explain higher mortality. The first factor discussed is the association between short height and decreased functional status. There is no reference for this hypothesis and no further discussion. This reader does not consider this hypothesis convincing. Secondly, the authors suggest smaller thoracic volume might significantly restrict the donor pool from which an individual candidate would require an organ. To some extent, this size constraint would seem to apply to pediatric heart transplant candidates as well. I shall return to comparative heart data in that light subsequently. The authors suggest that the numeric restriction of the lung donor pool by UNOS rules would result in longer wait time and higher wait list mortality. Indeed, the UNOS database covering the years 1999–2004 shows a median waiting time for pediatric lung candidates 6–10 yr of age >1000 days and for similarly aged heart transplant candidates less than 100 days (4)! The authors present no other possible factors to account for the difficult challenges of the pediatric lung transplant candidate
