Long-Term Mortality and Functional Outcomes After Extracorporeal Membrane Oxygenation in Critically Ill Adults: A Systematic Review and Meta-Analysis.

Abstract

To evaluate long-term all-cause mortality and functional outcomes among critically ill adults treated with extracorporeal membrane oxygenation (ECMO), including differences by ECMO modality and clinical indication. Ovid MEDLINE, Embase, Emcare, Central Register of Controlled Trials, and Scopus were searched to March 2025. Randomized controlled trials and observational studies reporting mortality or functional outcomes at or beyond 6 months in adults receiving ECMO were eligible for inclusion. A systematic review and meta-analysis were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and prospectively registered with PROSPERO (CRD420251002639). Two reviewers independently extracted data. Mortality was pooled using random-effects meta-analysis with 95% CIs. Prespecified subgroup analyses examined ECMO modality and clinical indication. Sensitivity analyses assessed the impact of missing outcome data. Functional outcomes were narratively synthesized due to heterogeneity. A total of 163 studies including 78,053 adults met inclusion criteria, with 59,454 adults in 156 of 163 studies (95.7%) contributing to mortality meta-analyses. At 1 year, pooled mortality was 37.2% (95% CI, 30.0-45.1%) in 13 of 33 venovenous ECMO studies (39.4%), 55.2% (95% CI, 50.2-60.1%) in 42 of 55 venoarterial ECMO studies (76.4%), and 74.4% (95% CI, 71.4-77.2%) in 14 of 24 (58.3%) extracorporeal cardiopulmonary resuscitation (ECPR) studies. Functional outcomes were reported in 38 of 163 studies (23.3%) in 7,876 survivors and were assessed using various instruments, most commonly the Cerebral Performance Category in 20 of 38 studies (52.6%), the World Health Organization Disability Assessment Schedule 2.0 in five of 38 studies (13.2%), and the modified Rankin Scale in five of 38 studies (13.2%). Long-term mortality following ECMO differed substantially by ECMO modality, ranging from 37.2% among adults receiving venovenous ECMO to 74.4% among adults receiving ECPR. Functional outcomes were inconsistently reported, limiting the understanding of functional recovery among survivors. Standardized reporting and benchmarking are required to better inform long-term prognosis, patient selection, and factors that may improve functional recovery after ECMO.