Recurrence in Congenital Diaphragmatic Hernia: A Multicenter, Post-discharge Pilot Study

Background: Previous work from the Congenital Diaphragmatic Hernia Study Group (CDHSG) identified factors associated with early (in-hospital) hernia recurrence. Multicenter data regarding post-discharge outcomes for CDH infants have not been previously available. A long-term follow-up (LTFU) extension of CDHSG data collection began a pilot study in 2021. Our objective was to assess diaphragmatic hernia recurrence rates in the first five years of life using a multicenter cohort of CDH infants. We hypothesized that defect size and minimally invasive (MIS) repair would be associated with recurrent CDH.

Methods: An international, multicenter database of CDH infants seen in follow-up was established amongst 4 centers. Data were collected retrospectively from the medical record at specific time points: perinatal, time of discharge, 2-years of age, and 5-years of age. The primary outcome was recurrence of CDH. Variables of interest included defect severity (CDHSG stage) and operative approach.

Results: A total of 472 CDH infants were treated during the study period. Of those, 367 (78%) patients survived to hospital discharge. Of the survivors, 297 (81%) had LTFU data. Mean birthweight was 3.0±0.6 kg, and mean gestational age was 38±2.5 weeks. 241 (81%) patients had follow-up data at 2-years (median age at follow-up 2.0 years,IQR 1.8–2.2), and 113 (38%) had data at 5-years (median age at follow-up 5.0 years,IQR 4.8–5.2). 65% of patients had low-risk (CDHSG Stage A/B) defects. Thirty-five (12%) patients had a recurrence at any time point (6 prior to discharge, 25 between discharge and two-years, 4 before the five-year visit). While 13% of left-sided CDH patients and 5% of right-sided CDH patients had a recurrence, the difference was not statistically significant(p=0.14). 17% of high-risk (Stage C/D) patients had a diaphragmatic hernia recurrence, compared to 8% of low-risk patients(p=0.02). Patients that received extra-corporeal life support were more likely to have a CDH recurrence at any time point (23% vs. 10%;p=0.03). Forty-eight (16%) patients underwent MIS repair. MIS repair was significantly associated with recurrence at any time point (35% MIS recurrence rate vs. 7% open;p < 0.001), with most MIS recurrences (15/17) occurring within the first 2 years of life. There was no difference in the rate of recurrence between patients who underwent patch versus primary repair(p=0.17), and none of the 8 patients who underwent primary repair with patch overlay had a recurrence. None of the six patients who died post-discharge had a CDH recurrence.

Conclusion: We found that CDH defect size, ECLS, and MIS repair were associated with post-discharge recurrence with most recurrences seen after discharge. These data can be used to counsel families and for centers to benchmark their recurrence rates over time. While additional investigation is needed, this work represents the first multicenter, international CDH collaboration focused on long-term outcomes.