Neurologic Outcomes of
ECMO
as a Bridge to Lung Transplantation Across Lung Allocation Policy Eras
Andrew Kalra, Christopher Wilcox, Gabrielle M. Knauer, Leon Fan, Akram M. Zaaqoq, Bo Soo Kim, Daniel Brodie, Errol L. Bush, Glenn J. R. Whitman, Sung‐Min Cho ABSTRACT
Background
Extracorporeal membrane oxygenation (ECMO) may be used as a bridge to lung transplantation (BTT). The 2017 transition from donation service area (DSA)‐based to 250‐nautical mile radius‐based lung allocation was designed to reduce geographic disparities, though concerns remained whether evolving patient acuity among ECMO‐supported candidates could influence acute brain injury (ABI) risk. We evaluated whether the policy change was associated with increased ABI.
Methods
We conducted a retrospective cohort study using the Extracorporeal Life Support Organization (2012–2023) Registry, including adults supported with respiratory ECMO as BTT. Patients were stratified relative to the DSA policy change. The primary outcome was ABI during ECMO support. The secondary outcome was in‐hospital mortality; exploratory analyses compared ABI and mortality between BTT and non‐BTT patients across allocation eras.
Results
Among 1034 ECMO BTT patients, 256 (24.7%) were treated pre‐DSA and 778 (75.3%) post‐DSA. Post‐DSA patients were older, had greater comorbidity burden, and exhibited more severe pre‐ECMO physiologic derangement ( p < 0.001 for all). ECMO duration was similar between eras (median 11 vs. 10 days, p = 0.12). Overall, 24 patients (2.3%) developed ABI: 8 (3.1%) pre‐DSA and 16 (2.1%) post‐DSA. Accounting for ECMO exposure time, ABI incidence was 2.06 per 1000 ECMO‐days (95% CI = 0.89–4.07) pre‐DSA versus 0.86 per 1000 ECMO‐days (95% CI = 0.49–1.40) post‐DSA, with no significant difference (incidence rate ratio = 0.42, 95% CI = 0.17–1.13). In multivariable analysis, treatment era was not independently associated with ABI (adjusted odds ratio = 1.58, 95% CI = 0.63–3.69).
Conclusions
Despite treating a higher‐risk population post‐DSA, we observed no significant association between allocation era and ABI. These findings suggest that broader lung allocation has not increased neurologic complications among ECMO BTT patients, though ABI event rates were low.