BACKGROUND: We compared early neurodevelopmental morbidity in young children with severe CDH who underwent FETO to those without fetal therapy.
METHODS: We conducted a prospective study of severe CDH patients undergoing FETO (n = 18) at a single North American center from 2015 to 2021 (NCT02710968). Outpatient survivors (n = 12) were evaluated by a multidisciplinary team and compared to expectantly managed CDH patients. Neurodevelopmental outcomes were assessed using the Capute Scales [Clinical Linguistic and Auditory Milestone Scales (CLAMS) and Cognitive Adaptive Test (CAT)], with a developmental quotient (DQ) < 85 indicative of at-risk for delay.
RESULTS: At one year, 58% (n = 7) of FETO patients underwent evaluation, with notable concern for language delay (CLAMS median DQ, 80.1 [interquartile range, 67.6-86.7]). FETO scores improved by 24-months, whereas high severity/non-FETO scores declined [CLAMS median DQ (Difference in DQ), 92.3 (+12.2) vs. 77.1 (-13.4), respectively; p = 0.049]. On the initial CAT, FETO patients had concern for visual motor and problem-solving delays, with a median DQ of 81.3 (62.1-89.4). At 24-months, FETO patients had improving scores [Median CAT DQ, 90.8 (+9.5)], whereas high severity/non-FETO [87.5 (-3.0), p = 0.28] had declining scores.
CONCLUSIONS: These initial data suggest that FETO is associated with favorable neurodevelopmental outcomes at 24-months compared to severe CDH under expectant management.
METHODS: III.

Fetal endoscopic tracheal occlusion (FETO) is an emerging surgical therapy for congenital diaphragmatic hernia (CDH). Ovine and rabbit data suggested altered lung epithelial cell populations after tracheal occlusion (TO) with transcriptomic signatures implicating basal cells. To test this hypothesis, we deconvolved mRNA sequencing (mRNA-seq) data and used quantitative image analysis in fetal rabbit lung TO, which had increased basal cells and reduced ciliated cells after TO. In a fetal mouse TO model, flow cytometry showed increased basal cells, and immunohistochemistry demonstrated basal cell extension to subpleural airways. Nuclear Yap, a known regulator of basal cell fate, was increased in TO lung, and Yap ablation on the lung epithelium abrogated TO-mediated basal cell expansion. mRNA-seq of TO lung showed increased activity of downstream Yap genes. Human lung specimens with congenital and fetal tracheal occlusion had clusters of subpleural basal cells that were not present in the control. TO increases lung epithelial cell nuclear Yap, leading to basal cell expansion.

OBJECTIVE: To report the longitudinal lung growth and prognosis of fetuses with severe left sided congenital diaphragmatic hernia (CDH) treated with fetoscopic tracheal occlusion (FETO) in a single institution.
METHODS: Fetal lung size (observed-to-expected lung area to head circumference [o/e-LHR]) was measured in seven consecutive fetuses with isolated severe left-sided CDH who underwent FETO. Fetal lung growth was used to prognosticate survival and need for ECMO.
RESULTS: Seven consecutive fetuses had a FETO procedure in the timeframe of this study. A total of 44 longitudinal ultrasound were performed to evaluate lung development. FETO was performed at GA 28.5 ± 0.5 weeks. Five (71.4%) infants survived to one-year follow-up and ECMO was needed in three patients (42.8%). Fetal lung response was observed in all fetuses; mean o/e-LHR increased from 22.5% ± 1.4 before FETO to 44.4% ± 9.8 before delivery. Infants who survived had a higher percentage of fetal lung growth (21.8%) than those who died (8.25%).
CONCLUSIONS: Our study supports the hypothesis that FETO promotes fetal lung growth in fetuses with severe left-sided CDH, and the fetal pulmonary response seems to be associated with improved outcomes after the procedure.

UNASSIGNED: To study the role of fetal endoscopic tracheal occlusion (FETO) on resolution of pulmonary hypertension (PH) in fetuses with isolated moderate left-sided diaphragmatic hernia (CDH).
UNASSIGNED: This retrospective study included fetuses with CDH evaluated between February 2004 and July 2017. Using the tracheal occlusion to accelerate lung growth (TOTAL) trial definition, we classified fetuses into moderate left CDH if O/E-LHR (observed/expected-lung head ratio) was 25-34.9% regardless of liver position or O/E-LHR of 35-44.9% if liver was in the chest. Postnatal echocardiograms were used to diagnose PH. Logistic regression analyses were performed to determine the relationship of FETO with study outcomes.
UNASSIGNED: Of 184 cases with no other major anomalies, 30 (16%) met criteria. There were nine FETO and 21 non-FETO cases. By hospital discharge, a higher proportion of infants in the FETO group had resolution of PH (87.5 (7/8) vs. 40% (8/20); p=.013). FETO was associated with adjusted odds ratio of 17.3 (95% CI: 1.75-171; p=.015) to resolve PH by hospital discharge. No significant differences were noted in need for ECMO or survival to discharge between groups.
UNASSIGNED: Infants with moderate left-sided CDH according to O/E-LHR, FETO is associated with resolution of PH by the time of hospital discharge.

OBJECTIVE: (1) To investigate the reproducibility of total fetal lung volume (TFLV) measurements using a free 3D modeling software (3DSlicer); (2) To correlate these measurements with lung-to-head ratio (LHR) or TFLV measured using PACS and; (3) To determine the role of 3DSlicer in predicting perinatal outcomes in cases with congenital diaphragmatic hernia (CDH) who had fetal tracheal occlusion (FETO).
METHODS: Retrospective cohort study between 2012 and 2017 at Texas Children\'s Hospital (2011-2017), including all patients who underwent FETO for CDH. LHR was measured by ultrasound and TFLV was measured by MRI at the time of referral and 6 weeks after FETO using 3DSlicer and PACS. We evaluated intra- and inter-rater reliability of TFLV measurement using 3DSlicer, infant survival to 1 year, need for ECMO and pulmonary hypertension.
RESULTS: The intra- and inter-rater reliability of TFLV measured with 3DSlicer was excellent before and after FETO (Intra-class correlation coefficient: 0.98-0.99 and 0.94-0.99, respectively). There was a good correlation between TFLV measured with PACS and with 3DSlicer before and after FETO (r = 0.78 and r = 0.99, respectively). Similarly, there was a good correlation between TFLV measurements using PACS or 3DSlicer and LHR after FETO (r = 0.86 and r = 0.88, respectively). Infants who survived to 1 year had a significantly higher TFLV evaluated with 3DSlicer before FETO compared to non-surviving infants (OR = 1.16[1.1-1.3], p = 0.03) as well as a significantly higher TFLV evaluated by 3DSlicer after FETO (OR = 1.2[1-1.4], p = 0.04).
CONCLUSIONS: Lung volume measurements using free 3DSlicer in infants with severe CDH who underwent FETO are reproducible and reliable, and have comparable predictive capability for survival as those measured using conventional software.

There is a certain need for reversible, cheap, and reproducible animal models for understanding the impact of tracheal occlusion (TO) in the congenital diaphragmatic hernia and pathophysiology. We aimed to present an easy, reversible, and minimally invasive murine TO model with optimized time points for introduction and removal of TO.
Time-mated C57BL/6 mice underwent laparotomy at embryonic day 16.5 (E16.5) with transuterine TO performed on two fetuses in each uterine horn. In the TO group, the fetuses were harvested at E18.5 without suture removal; the suture was released at E17.5 in the TO-R group, and all fetuses were harvested at E18.5. The lungs of the fetuses were compared by morphometric and histologic analysis.
Successful TO was confirmed in 34 of 37 fetuses. Twenty-nine of them survived to E18.5 (90.6%), six of the fetuses had a spontaneous vaginal delivery. Fetal weights were comparable, but there was significant difference in lung weights and lung-to-body weight ratios (0.020 ± 0.006 [control] versus 0.026 ± 0.002 [TO] versus 0.023 ± 0.005 [TO-R]; P = 0.013). DNA/protein and DNA/lung weight ratios were elevated, whereas protein/lung weight ratio was lower in TO compared with the control group.
Reversal of fetal transuterine TO at E17.5, which was put at E16.5 in mice, is feasible with comparable outcomes to other current animal models with certain advantages and potential to translate the studies to the human.

Fetal tracheal occlusion (TO) is an emerging surgical therapy in congenital diaphragmatic hernia that improves the fetal lung growth. Different animal models of congenital diaphragmatic hernia and TO present advantages and disadvantages regarding ethical issues, cost, surgical difficulty, size, survival rates, and available genetic tools. We developed a minimally invasive murine transuterine TO model, which will be useful in defining how TO impacts lung molecular biology, cellular processes, and overall lung physiology.
Time-mated C57BL/6 mice underwent laparotomy at embryonic day 16.5 (E16.5) with transuterine TO performed on two fetuses in each uterine horn. At E18.5, dams were sacrificed and fetuses harvested. The lungs of the TO fetuses were compared with the nonmanipulated counterparts by morphometric and histologic analysis.
Successful TO was confirmed in 16 of 20 TO fetuses. Twelve of them survived to E18.5 (75%). Fetal weights were comparable, but lung weights were significantly greater in TO (28.41 ± 5.87 versus 23.38 ± 3.09, P = 0.043). Lung to body weight ratio was also greater (0.26 ± 0.003 versus 0.22 ± 0.002, P = 0.006). E18.5 TO lungs demonstrated dilated central and distal airspaces with increased cellularity. DNA/protein and DNA/lung weight ratios were elevated while protein/lung weight ratio was lower in TO compared to control.
Mice fetal transuterine TO is feasible with comparable outcomes to other current animal models. The increase in the lung weight, lung to body weight ratio and the DNA/protein ratio indicate organized lung growth rather than edema or cell hypertrophy.

In congenital diaphragmatic hernia (CDH), herniation of the abdominal organs into the fetal chest causes pulmonary hypoplasia and pulmonary hypertension, the main causes of neonatal mortality. As antenatal ultrasound screening improves, the risk of postnatal death can now be better predicted, allowing for the identification of fetuses that might most benefit from a prenatal intervention. Fetoscopic tracheal occlusion is being evaluated in a large international randomized controlled trial. We present the antenatal imaging approaches that can help identify fetuses that might benefit from antenatal therapy, and review the evolution of fetal surgery for CDH to date.

Survivors of severe congenital diaphragmatic hernia (CDH) present significant respiratory morbidity despite lung growth induced by fetal tracheal occlusion (TO). We hypothesized that the underlying mechanisms would involve changes in lung extracellular matrix and dysregulated transforming growth factor (TGF)-β pathway, a key player in lung development and repair. Pulmonary expression of TGF-β signaling components, downstream effectors, and extracellular matrix targets were evaluated in CDH neonates who died between birth and the first few weeks of life after prenatal conservative management or TO, and in rabbit pups that were prenatally randomized for surgical CDH and TO vs. sham operation. Before tissue harvesting, lung tissue mechanics in rabbits was measured using the constant-phase model during the first 30 min of life. Human CDH and control fetal lungs were also collected from midterm onwards. Human and experimental CDH did not affect TGF-β/Smad2/3 expression and activity. In human and rabbit CDH lungs, TO upregulated TGF-β transcripts. Analysis of downstream pathways indicated increased Rho-associated kinases to the detriment of Smad2/3 activation. After TO, subtle accumulation of collagen and α-smooth muscle actin within alveolar walls was detected in rabbit pups and human CDH lungs with short-term mechanical ventilation. Despite TO-induced lung growth, mediocre lung tissue mechanics in the rabbit model was associated with increased transcription of extracellular matrix components. These results suggest that prenatal TO increases TGF-β/Rho kinase pathway, myofibroblast differentiation, and matrix deposition in neonatal rabbit and human CDH lungs. Whether this might influence postnatal development of sustainably ventilated lungs remains to be determined.

In recent decades, new research into the developmental defects and pathophysiological basis of congenital diaphragmatic hernia (CDH) has revealed opportunities for the development of innovative therapies. Importantly, the use of animal models to represent this anomaly in the laboratory has resulted in the discovery of many important genetic, epigenetic, and other molecular contributors to this condition. In this review, the most commonly used and newly devised animal models of CDH are presented to familiarize the reader with the latest innovations in the basic sciences.