OBJECTIVE To measure the survival among comparable neonates with CDH supported with and without ECLS. SUMMARY OF BACKGROUND DATA Despite widespread use in the management of newborns with CDH, ECLS has not been consistently associated with improved survival. METHODS A retrospective cohort study was performed using ECLS-eligible CDH Study Group registry patients born between 2007 and 2019. The primary outcome was in-hospital mortality. Neonates who did and did not receive ECLS were matched based on variables affecting risk for the primary outcome. Iterative propensity score-matched, survival (Cox regression and Kaplan-Meier), and center effects analyses were performed to examine the association of ECLS use and mortality. RESULTS Of 5855 ECLS-eligible CDH patients, 1701 (29.1%) received ECLS. "High-risk" patients were best defined as those with a lowest achievable first-day arterial partial pressure of CO2 of ≥60 mm Hg. After propensity score matching, mortality was higher with ECLS (47.8% vs 21.8%, odds ratio 3.3, 95% confidence interval 2.7-4.0, hazard ratio 2.3, P < 0.0001). For the subgroup of high-risk patients, there was lower mortality observed with ECLS (64.2% vs 84.4%, odds ratio 0.33, 95% confidence interval 0.17-0.65, hazard ratio 0.33, P = 0.001). This survival advantage was persistent using multiple matching approaches. However, this ECLS survival advantage was found to occur primarily at high CDH volume centers that offer frequent ECLS for the high-risk subgroup. CONCLUSIONS Use of ECLS is associated with excess mortality for low- and intermediate-risk neonates with CDH. It is associated with a significant survival advantage among high-risk infants, and this advantage is strongly influenced by center CDH volume and ECLS experience.
