Exceptional LAS Requests in Eurotransplant: Analysis of an 8-year Effort to Improve Lung Allocation for Precarious Patients

Abstract

PURPOSE: Following introduction of the lung allocation score (LAS) in 2011, Eurotransplant member centers can apply for an exceptional LAS (eLAS) if the calculated LAS insufficiently reflects the perceived transplant benefit for a patient, specifically in case of primary pulmonary hypertension group 1 and 4; combined lung+non-renal transplantation; rare diseases; or extracorporeal support. Each eLAS proposal is evaluated by a LAS Review Board, consisting of ≥3 lung transplant experts, which subsequently declines or approves the eLAS request in consensus of ≥3 votes. In case of a lower than accepted score, predefined business rules to assign LAS percentiles are used. METHODS: A retrospective analysis of all eLAS requests in Eurotransplant from December 2011 until September 2019. RESULTS: Overall, 5183 lung transplants (deceased donors) were performed and 420 eLAS requests were made (Germany 52%, Netherlands 18%, Austria 18%, Belgium 13%), of which 116 (28%) were approved. Most eLAS requests concerned group B/Pulmonary vascular disease (44%), followed by group C/Cystic fibrosis or immunodeficiency disorder (28%), then group D/Restrictive lung disease (15%) and finally group A/Obstructive lung disease (11%); whereas 10 patients (2%) were not classified. The proportion of accepted eLAS requests significantly differed between countries (Germany 25%, Netherlands 37%, Austria 20%, Belgium 36%) (p=0.042). eLAS requests decreased in the Netherlands following its LAS introduction in 2014 (2011-2014 mean 13/yr vs. 2015-2019 mean 4.6/yr; p=0.060). However, since 2015 an overall annual increasing number of eLAS requests is seen, with doubling of the eLAS requests in 2018 vs. 2015, but no difference in acceptance rate (2015-2018: 22.4%) (Figure). Acceptance rates were 38% for Group B, 21% for Group C, 20% for Group D and 11% for Group A. CONCLUSION: The observed variations require further investigation to optimize lung allocation for specific patient populations in Eurotransplant.