The Timing of Congenital Diaphragmatic Hernia Repair on Extracorporeal Membrane Oxygenation Impacts Surgical Bleeding Risk

Background: The optimal timing of surgical repair for infants with congenital diaphragmatic hernia (CDH) treated with extracorporeal membrane oxygenation (ECMO) support remains controversial. The risk of surgical bleeding is considered by many centers as a primary factor in determining the preferred timing of CDH repair for infants requiring ECMO support. This study compares surgical bleeding following CDH repair on ECMO in early versus delayed fashion. Methods: A retrospective review of 146 infants who underwent CDH repair while on ECMO support from 1995 to 2021. Early repair occurred during the first 48 h after ECMO cannulation (ER) and delayed repair after 48 h (DR). Surgical bleeding was defined by the requirement of reoperative intervention for hemostasis or decompression. Results: 102 infants had ER and 44 infants DR. Surgical bleeding was more frequent in the DR group (36% vs 5%, p < 0.001) with an odds ratio of 11.7 (95% CI: 3.48-39.3, p < 0.001). Blood urea nitrogen level on the day of repair was significantly elevated among those who bled (median 63 mg/dL, IQR 20-85) vs. those who did not (median 9 mg/dL, IQR 7-13) (p < 0.0001). Duration of ECMO support was shorter in the ER group ( median 13 vs 18 days, p = 0.005). Survival was not statistically different between the two groups (ER 60% vs. DR 57%, p =0.737). Conclusion: We demonstrate a significantly lower incidence of bleeding and shorter duration of ECMO with early CDH repair. Azotemia was a strong risk factor for surgical bleeding associated with delayed CDH repair on ECMO. Level of evidence: Level III cohort study.