(593) Suboptimal Fetal Lung Growth After Fetal Endoluminal Tracheal Occlusion in Congenital Diaphragmatic Hernia: Clinical Characteristics

Suboptimal fetal lung growth (SFLG) affects cases that undergo Fetoscopic endoluminal tracheal occlusion(FETO) in severe left-sided congenital diaphragmatic hernia (L-CDH).We describe the demographic and clinical characteristics of SFLG  and optimal fetal lung growth (OFLG) after FETO


Study Design:

Singleton pregnancies with isolated L-CDH,defined as observed-to-expected lung-to-head ratio (O/E LHR) < 25% and normal chromosomes, underwent FETO under an IRB- and FDA-approved clinical trial protocol (NCT02596802) at the UTHealth Houston Fetal Center from 2015-2024. The FETO  balloon insertion was scheduled at 27-30 weeks' gestation (wGA),and balloon removal at 34-35-wGA.Observed-to-expected total fetal lung volume (O/E TFLV) was measured by MRI before and 3 weeks after FETO, and percent changes from pre- to post-FETO MRIs were calculated.Descriptive, analytical statistics and (ROC) curve analysis associating metrics with neonatal survival and the need for extracorporeal life support (ECLS)  were performed via R interface(jamovi.org).

Results:

19 pregnant women were enrolled, 4 children died, 2  cases did not undergo the post-FETO-MRI, 2 cases died before surgical repair.Area under the ROC curve(AUC) of O/E TFLV for the prediction of survival and not need for ECLS were 0.974, and  0.729, respectively.The best cut-off for identification of SFLG was an increase of < 12.8%  of O/E TFLV 21 days post-FETO with a sensitivity of 92.3% and specificity of 100% to predict childhood mortality at hospital discharge.An increase of ≥ 12.8 % of TFLV(OFLG) had a sensitivity of 90% and specificity of 57.1% to predict children that do not require ECLS.  Demographic and maternal characteristics were not different between  SFLG and OFLG(Table 1). SFLG  had lower  O/E TFLV and O/E LHR three weeks post-FETO,and was associated with a lower frequency of surviving hospital discharge than OFLG(Table 2).                                                                                                                                                                                                                                                                                                            

Conclusion: SFLG,characterized by decreased lung volume, is associated with a lower survival than optimal fetal lung growth.