Fetoscopic endoluminal tracheal occlusion and reestablishment of fetal airways for congenital diaphragmatic hernia

Fetal surgery using fetoscopic endoluminal tracheal occlusion for severe congenital diaphragmatic hernia: a single-center experience

PURPOSE

To provide a comprehensive report of the experience gained in the prenatal treatment of congenital diaphragmatic hernia (CDH) using fetoscopic endoluminal tracheal occlusion (FETO) following its implementation at a newly established specialized fetal medicine center.

METHODS

Mothers of fetuses with severe CDH were offered prenatal treatment by FETO.

RESULTS

Between 2018 and 2021, 16 cases of severe CDH underwent FETO. The median gestational age (GA) at balloon insertion was 28.4 weeks (IQR 27.8-28.6). The median GA at delivery was 37 weeks (IQR 34.4-37.8). The survival rate was 8/16 cases (50%). None of the survivors required home oxygen therapy at 6 months of age. Comparison between the survivors and deceased showed that survivors had balloon insertion 1 week earlier (27.8 vs. 28.4 weeks, p = 0.007), a higher amniotic fluid level change between pre- to post-FETO (3.4 vs 1.3, p = 0.024), a higher O/E LHR change between pre- to post-FETO (50.8 vs. 37.5, p = 0.047), and a GA at delivery that was 2 weeks later (37.6 vs. 35.4 weeks, p = 0.032).

CONCLUSIONS

The survival rate at 6 months of age in cases of severe CDH treated with FETO in our center was 50%. Our new fetal medicine center matches the performance of other leading international centers.

Risk factors and outcome of antenatally diagnosed congenital diaphragmatic hernia following in-utero transfer in a busy public-sector tertiary care center in North India

We analyzed the risk factors and outcomes of antenatally diagnosed congenital diaphragmatic hernia (CDH) from a tertiary-care children's hospital following in-utero transfer. A total of 41 antenatally detected cases of CDH were included; 30 were live-born and 11 were still-born. The primary outcome was postnatal survival. The secondary outcome was the probable factor affecting survival. No medical termination of the pregnancy was done. The mean gestational age at diagnosis was 23 weeks. The diagnostic accuracy of antenatal ultrasonography was 40/41 (97.5%). Lung-to-head ratio (LHR) was <1 in 20 cases (survived 2), LHR was >1 in 10 cases (survived 8), and LHR was not recorded in 11 cases (survived 4). Overall survival was 14/41 (34.1%). Survival in fetuses with polyhydramnios was 0% (n=3; survived 0), associated anomalies were 33.3% (n=3; survived 1), and liver herniation was 22.2% (n=9; survived 2). Postnatally, significant risk factors included a low Apgar score, the need for ventilation, and neonatal intensive care unit (NICU) management. Survival in live-born cases was 14/30 (46.6%) and in operated cases was 14/19 (73.6%). We concluded that antenatal ultrasound had a high accuracy rate for detecting CDH. Antenatal risk factors affecting outcomes were low LHR, maternal polyhydramnios, liver herniation, and associated malformations. Postnatal risk factors included a low Apgar score, NICU admission, and a need for ventilation. The overall survival rate, as well as the survival rates for live-borns and those undergoing surgery, were 34.1%, 46.6%, and 73.6%, respectively. This data will guide clinicians in counseling the families of antenatally diagnosed CDH.

Prenatal ultrasound, magnetic resonance imaging and therapeutic options for fetal thoracic anomalies: a pictorial essay

Congenital thoracic anomalies are uncommon malformations that require a precise diagnosis to guide parental counseling and possible prenatal treatment. Prenatal ultrasound (US) is the gold standard imaging modality to first detect and characterize these abnormalities and the best modality for follow-up. Fetal magnetic resonance imaging (MRI) is a complementary tool that provides multiplanar assessment and tissue characterization and can help estimate prognosis. Prenatal treatment is increasingly being used in fetuses with signs of distress and to potentially decrease morbidity and mortality. In this essay, the authors illustrate side-by-side US, MRI and therapeutic options for congenital thoracic anomalies in cases that presented to a tertiary pediatric hospital during the 7-year period 2014-2021. Entities included are congenital diaphragmatic hernia, congenital pulmonary airway malformation, bronchopulmonary sequestration, hybrid lesions, foregut duplications cysts and congenital lobar overinflation. Treatment options include maternal steroids, thoraco-amniotic shunt and fetal endotracheal occlusion. Recognition of typical findings in congenital thoracic anomalies is helpful to establish diagnosis, predict prognosis and plan perinatal treatment.

Fetoscopic endoluminal tracheal occlusion with Smart-TO balloon: Study protocol to evaluate effectiveness and safety of non-invasive removal

INTRODUCTION

One of the drawbacks of fetoscopic endoluminal tracheal occlusion (FETO) for congenital diaphragmatic hernia is the need for a second invasive intervention to reestablish airway patency. The "Smart-TO" (Strasbourg University-BSMTI, France) is a new balloon for FETO, which spontaneously deflates when positioned near a strong magnetic field, e.g., generated by a magnetic resonance image (MRI) scanner. Translational experiments have demonstrated its efficacy and safety. We will now use the Smart-TO balloon for the first time in humans. Our main objective is to evaluate the effectiveness of prenatal deflation of the balloon by the magnetic field generated by an MRI scanner.

MATERIAL AND METHODS

These studies were first in human (patients) trials conducted in the fetal medicine units of Antoine-Béclère Hospital, France, and UZ Leuven, Belgium. Conceived in parallel, protocols were amended by the local Ethics Committees, resulting in some minor differences. These trials were single-arm interventional feasibility studies. Twenty (France) and 25 (Belgium) participants will have FETO with the Smart-TO balloon. Balloon deflation will be scheduled at 34 weeks or earlier if clinically required. The primary endpoint is the successful deflation of the Smart-TO balloon after exposure to the magnetic field of an MRI. The secondary objective is to report on the safety of the balloon. The percentage of fetuses in whom the balloon is deflated after exposure will be calculated with its 95% confidence interval. Safety will be evaluated by reporting the nature, number, and percentage of serious unexpected or adverse reactions.

CONCLUSION

These first in human (patients) trials may provide the first evidence of the potential to reverse the occlusion by Smart-TO and free the airways non-invasively, as well a safety data.

Prenatal management of congenital diaphragmatic hernia

Recently, two randomized controlled, prospective trials, the Tracheal Occlusion to Accelerate Lung Growth (TOTAL) trials, reported the outcomes on fetal endoluminal tracheal occlusion (FETO) for isolated left congenital diaphragmatic hernia (CDH). FETO significantly improved outcomes for severe hypoplasia. The effect in moderate cases, where the balloon was inserted later in pregnancy, did not reach significance. In a pooled analysis investigating the effect of the heterogeneity of the treatment effect by the time point of occlusion and severity, the difference may be explained by a difference in the duration of occlusion. Nevertheless, FETO carries a significant risk of preterm birth. The primary objective of this review is to provide an overview of the rationale for fetal intervention in CDH and the results of the randomized trials. The secondary objective is to discuss the technical aspects of FETO. Finally, recent developments of potential alternative fetal approaches will be highlighted.

Assessment of the fetal lungs in utero

Antenatal diagnosis of abnormal pulmonary development has improved significantly over recent years because of progress in imaging techniques. Two-dimensional ultrasound is the mainstay of investigation of pulmonary pathology during pregnancy, providing good prognostication in conditions such as congenital diaphragmatic hernia; however, it is less validated in other high-risk groups such as those with congenital pulmonary airway malformation or preterm premature rupture of membranes. Three-dimensional assessment of lung volume and size is now possible using ultrasound or magnetic resonance imaging; however, the use of these techniques is still limited because of unpredictable fetal motion, and such tools have also been inadequately validated in high-risk populations other than those with congenital diaphragmatic hernia. The advent of advanced, functional magnetic resonance imaging techniques such as diffusion and T2* imaging, and the development of postprocessing pipelines that facilitate motion correction, have enabled not only more accurate evaluation of pulmonary size, but also assessment of tissue microstructure and perfusion. In the future, fetal magnetic resonance imaging may have an increasing role in the prognostication of pulmonary abnormalities and in monitoring current and future antenatal therapies to enhance lung development. This review aims to examine the current imaging methods available for assessment of antenatal lung development and to outline possible future directions.

Crossing birth and mortality data as a clue for prevalence of congenital diaphragmatic hernia in Sao Paulo State: A cross sectional study

Background

Congenital diaphragmatic hernia (CDH) is a severe embryological defect that causes pulmonary hypoplasia and hypertension. The prevalence and mortality rate of CDH varies around the world and little information is available about CDH in Latin America. Our aim was to estimate the general prevalence, mortality rate, prevalence of associated anomalies and features related to the outcomes of CDH in newborns from São Paulo state, Brazil.

Methods

Population-based cross-sectional study based on data gathered from the Live Births Information System (SINASC) and the Mortality Information System (SIM) of children born in São Paulo state between January 1st, 2006, and December 31st, 2017.

Findings

From 7,311,074 total survival discharges between 2006 and 2017, 1,155 were CDH-related, resulting in a prevalence rate of 1:6329 (95%CI = 1/6715 - 1/5984) and a mortality rate of 63·72% (95%CI = 60.95 - 66.50), 510 presented complex associated anomalies (44·15%). Maternal data showed higher prevalence among older mothers (older than 35 years old: 2·13 per 10,000) and, also, women with more years of schooling (higher than 12 years: 1·99 per 10,000). Presence of associated anomalies (95%CI = 5.69-11.10), 1-min Apgar (95%CI = 1.44-2.95), maternal schooling (95%CI = 1.06-2.43) and birth weight (95%CI = 1.04-2.26) were the most significant features associated with mortality.

Interpretation

There was 1 CDH case for every 6329 newborns in São Paulo and the mortality rate among those cases was 63·72% - a high rate compared to other countries.

Funding

This study didn't receive any specific grant from any funding agency in the public, commercial or not-for-profit sectors.

The randomized Tracheal Occlusion To Accelerate Lung growth (TOTAL)-trials on fetal surgery for congenital diaphragmatic hernia: reanalysis using pooled data

BACKGROUND

Two randomized controlled trials compared the neonatal and infant outcomes after fetoscopic endoluminal tracheal occlusion with expectant prenatal management in fetuses with severe and moderate isolated congenital diaphragmatic hernia, respectively. Fetoscopic endoluminal tracheal occlusion was carried out at 27⁺⁰ to 29⁺⁶ weeks' gestation (referred to as "early") for severe and at 30⁺⁰ to 31⁺⁶ weeks ("late") for moderate hypoplasia. The reported absolute increase in the survival to discharge was 13% (95% confidence interval, -1 to 28; P=.059) and 25% (95% confidence interval, 6-46; P=.0091) for moderate and severe hypoplasia.

OBJECTIVE

Data from the 2 trials were pooled to study the heterogeneity of the treatment effect by observed over expected lung-to-head ratio and explore the effect of gestational age at balloon insertion.

STUDY DESIGN

Individual participant data from the 2 trials were reanalyzed. Women were assessed between 2008 and 2020 at 14 experienced fetoscopic endoluminal tracheal occlusion centers and were randomized in a 1:1 ratio to either expectant management or fetoscopic endoluminal tracheal occlusion. All received standardized postnatal management. The combined data involved 287 patients (196 with moderate hypoplasia and 91 with severe hypoplasia). The primary endpoint was survival to discharge from the neonatal intensive care unit. The secondary endpoints were survival to 6 months of age, survival to 6 months without oxygen supplementation, and gestational age at live birth. Penalized regression was used with the following covariates: intervention (fetoscopic endoluminal tracheal occlusion vs expectant), early balloon insertion (yes vs no), observed over expected lung-to-head ratio, liver herniation (yes vs no), and trial (severe vs moderate). The interaction between intervention and the observed over expected lung-to-head ratio was evaluated to study treatment effect heterogeneity.

RESULTS

For survival to discharge, the adjusted odds ratio of fetoscopic endoluminal tracheal occlusion was 1.78 (95% confidence interval, 1.05-3.01; P=.031). The additional effect of early balloon insertion was highly uncertain (adjusted odds ratio, 1.53; 95% confidence interval, 0.60-3.91; P=.370). When combining these 2 effects, the adjusted odds ratio of fetoscopic endoluminal tracheal occlusion with early balloon insertion was 2.73 (95% confidence interval, 1.15-6.49). The results for survival to 6 months and survival to 6 months without oxygen dependence were comparable. The gestational age at delivery was on average 1.7 weeks earlier (95% confidence interval, 1.1-2.3) following fetoscopic endoluminal tracheal occlusion with late insertion and 3.2 weeks earlier (95% confidence interval, 2.3-4.1) following fetoscopic endoluminal tracheal occlusion with early insertion compared with expectant management. There was no evidence that the effect of fetoscopic endoluminal tracheal occlusion depended on the observed over expected lung-to-head ratio for any of the endpoints.

CONCLUSION

This analysis suggests that fetoscopic endoluminal tracheal occlusion increases survival for both moderate and severe lung hypoplasia. The difference between the results for the Tracheal Occlusion To Accelerate Lung growth trials, when considered apart, may be because of the difference in the time point of balloon insertion. However, the effect of the time point of balloon insertion could not be robustly assessed because of a small sample size and the confounding effect of disease severity. Fetoscopic endoluminal tracheal occlusion with early balloon insertion in particular strongly increases the risk for preterm delivery.

Antenatal Management of Congenital Diaphragmatic Hernia: what's next ?

Congenital diaphragmatic hernia (CDH) can be diagnosed in the prenatal period and its severity can be measured by fetal imaging. There is now level I evidence that, in selected cases, Fetoscopic Endoluminal Tracheal Occlusion (FETO) increases survival to discharge from the neonatal unit as well as the risk for prematurity. Both effects are dependent on the time point of tracheal occlusion. FETO may also lead to iatrogenic death when done in unexperienced centres. The implementation of the findings from our clinical studies, may also vary based on local conditions. These may be different in terms of available skill set, access to fetal therapy, as well as outcome based on local neonatal management. We encourage prior benchmarking of local outcomes with optimal postnatal management, based on large enough numbers and using identical criteria as in the recent trials. We propose to work further on prenatal prediction methods, and the improvement of fetal intervention. In this manuscript, we describe a research agenda from a fetal medicine perspective. This research should be in parallel with innovation in neonatal and pediatric (surgical) management of this condition. This article is protected by copyright. All rights reserved.

How should fetal surgery for congenital diaphragmatic hernia be implemented in the post-TOTAL trial era: a discussion. Prenat Diagn 2022;42:301-309. [PMID: 35032132 DOI: 10.1002/pd.6091]

Following prenatal diagnosis of congenital diaphragmatic hernia, severity can be predicted based on the presence of associated abnormalities, and in isolated cases, on lung size and position of the liver. Severe hypoplasia is defined by a contralateral lung size < 25% on ultrasound; moderate hypoplasia is when that lung measures between 25 and 45% of the normal. In fetuses with predicted poor postnatal outcome a procedure that reverses pulmonary hypoplasia may be considered. In uncontrolled studies, fetoscopic endoluminal tracheal occlusion (FETO) improved neonatal outcome. Recently, two randomized controlled trials compared the neonatal and infant outcomes in fetuses with isolated CDH (www.totaltrial.eu). In severe cases, FETO was carried out at 27⁺⁰ -29⁺⁶ weeks' gestation (referred to as "early") and in moderate at 30⁺⁰ -31⁺⁶ weeks ("late"). Survival to discharge from the neonatal intensive care unit increased by 25% (95%-CI:+6 - +46; P=.0091) and 13% (-1 - +28; P=.059), in fetuses with severe and moderate cases, respectively. Following FETO gestational age at delivery was on average 3.2 (2.3-4.1) weeks earlier following early and 1.7 (1.1 - 2.3) following late FETO. Here the strengths and weaknesses of the TOTAL trials and their translation to the clinic are debated. Discussants are the lead for the trial (JD) and a colleague (AF) not involved. The discussant notes that the observed survival, both in treated and expectantly managed fetuses, was overall less than what is reported by some high volume centers, particularly in North America. Additional criticisms are the potential effects of prematurity on the long term, the inclusion of low-volume centers, and the potential of FETO for severe iatrogenic complications. Therefore results may not be generalizable. The discussants concluded that although FETO may have its value it remains a procedure with a high risk for prematurity and it can be lethal when the balloon cannot be removed prior to delivery. This article is protected by copyright. All rights reserved.

The role of magnetic resonance imaging in the diagnosis and prognostic evaluation of fetuses with congenital diaphragmatic hernia

In recent years, magnetic resonance imaging (MRI) has largely increased our knowledge and predictive accuracy of congenital diaphragmatic hernia (CDH) in the fetus. Thanks to its technical advantages, better anatomical definition, and superiority in fetal lung volume estimation, fetal MRI has been demonstrated to be superior to 2D and 3D ultrasound alone in CDH diagnosis and outcome prediction. This is of crucial importance for prenatal counseling, risk stratification, and decision-making approach. Furthermore, several quantitative and qualitative parameters can be evaluated simultaneously, which have been associated with survival, postnatal course severity, and long-term morbidity.

CONCLUSION

Fetal MRI will further strengthen its role in the near future, but it is necessary to reach a consensus on indications, methodology, and data interpretation. In addition, it is required data integration from different imaging modalities and clinical courses, especially for predicting postnatal pulmonary hypertension. This would lead to a comprehensive prognostic assessment.

WHAT IS KNOWN

• MRI plays a key role in evaluating the fetal lung in patients with CDH. • Prognostic assessment of CDH is challenging, and advanced imaging is crucial for a complete prenatal assessment and counseling.

WHAT IS NEW

• Fetal MRI has strengthened its role over ultrasound due to its technical advantages, better anatomical definition, superior fetal lung volume estimation, and outcome prediction. • Imaging and clinical data integration is the most desirable strategy and may provide new MRI applications and future research opportunities.

Professional integrity in maternal - fetal innovation and research: an essential component of perinatal medicine

OBJECTIVES

Clinical innovation and research on maternal-fetal interventions have become an essential for the development of perinatal medicine. In this paper, we present an ethical argument that the professional virtue of integrity should guide perinatal investigators.

METHODS

We present an historical account of the professional virtue of integrity and the key distinction that this account requires between intellectual integrity and moral integrity.

RESULTS

We identify implications of both intellectual and moral integrity for innovation, research, prospective oversight, the role of equipoise in randomized clinical trials, and organizational leadership to ensure that perinatal innovation and research are conducted with professional integrity.

CONCLUSIONS

Perinatal investigators and those charged with prospective oversight should be guided by the professional virtue of integrity. Leaders in perinatal medicine should create and sustain an organizational culture of professional integrity in fetal centers, where perinatal innovation and research should be conducted.

A maChine and deep Learning Approach to predict pulmoNary hyperteNsIon in newbornS with congenital diaphragmatic Hernia (CLANNISH): Protocol for a retrospective study

INTRODUCTION

Outcome predictions of patients with congenital diaphragmatic hernia (CDH) still have some limitations in the prenatal estimate of postnatal pulmonary hypertension (PH). We propose applying Machine Learning (ML), and Deep Learning (DL) approaches to fetuses and newborns with CDH to develop forecasting models in prenatal epoch, based on the integrated analysis of clinical data, to provide neonatal PH as the first outcome and, possibly: favorable response to fetal endoscopic tracheal occlusion (FETO), need for Extracorporeal Membrane Oxygenation (ECMO), survival to ECMO, and death. Moreover, we plan to produce a (semi)automatic fetus lung segmentation system in Magnetic Resonance Imaging (MRI), which will be useful during project implementation but will also be an important tool itself to standardize lung volume measures for CDH fetuses.

METHODS AND ANALYTICS

Patients with isolated CDH from singleton pregnancies will be enrolled, whose prenatal checks were performed at the Fetal Surgery Unit of the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico (Milan, Italy) from the 30th week of gestation. A retrospective data collection of clinical and radiological variables from newborns' and mothers' clinical records will be performed for eligible patients born between 01/01/2012 and 31/12/2020. The native sequences from fetal magnetic resonance imaging (MRI) will be collected. Data from different sources will be integrated and analyzed using ML and DL, and forecasting algorithms will be developed for each outcome. Methods of data augmentation and dimensionality reduction (feature selection and extraction) will be employed to increase sample size and avoid overfitting. A software system for automatic fetal lung volume segmentation in MRI based on the DL 3D U-NET approach will also be developed.

ETHICS AND DISSEMINATION

This retrospective study received approval from the local ethics committee (Milan Area 2, Italy). The development of predictive models in CDH outcomes will provide a key contribution in disease prediction, early targeted interventions, and personalized management, with an overall improvement in care quality, resource allocation, healthcare, and family savings. Our findings will be validated in a future prospective multicenter cohort study.

REGISTRATION

The study was registered at ClinicalTrials.gov with the identifier NCT04609163.

The novel fetal MRI O/E CLV versus O/E LHR in predicting prognosis in congenital diaphragmatic hernias: can we teach an old dog new tricks?

PURPOSE

In congenital diaphragmatic hernia (CDH), ultrasound (U/S) measurements of the contralateral lung commonly provide the observed-to-expected lung-to-head ratio (O/E LHR) and are used to determine the severity of pulmonary hypoplasia. Fetal magnetic resonance imaging (MRI) measurement of the observed-to-expected total lung volume (O/E TLV) has been used as an adjunct to O/E LHR in predicting outcomes. Since O/E LHR only measures the contralateral lung, we sought to investigate if MRI measurements of the contralateral lung volume (O/E CLV) can accurately predict outcomes in CDH. We hypothesize that O/E CLV is a better predictor of CDH outcomes than O/E LHR.

METHODS

We identified all infants with a prenatal diagnosis of CDH at our fetal center who had both MRI and U/S measurements. Using lung volume ratios of right-left 55:45, we calculated O/E CLV from O/E TLV. We used receiver-operating characteristic (ROC) curves to calculate the area under the curve (AUC) to compare the predictive accuracy of O/E CLV to O/E LHR for ECMO support, as well as survival to both discharge and 1 year.

RESULTS

Seventy-four patients had complete prenatal imaging with 39% requiring ECMO support. The median O/E CLV was 48.0% and the median O/E LHR was 42.3%. O/E CLV was a better predictor of the need for ECMO support (AUC 0.81 vs. 0.74). O/E CLV was a better predictor of survival to discharge (AUC 0.84 vs. 0.64) and 1-year survival (AUC 0.83 vs. 0.63) than O/E LHR.

CONCLUSION

O/E LHR is a well-validated standard for predicting outcomes and guiding prenatal counseling in CDH. We provide evidence that fetal MRI measurements of the contralateral lung volume corrected for gestational age were more accurate in predicting the need for ECMO and survival. Future prospective studies validating O/E CLV regarding outcomes and ECMO utilization are warranted.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Stretch increases alveolar type 1 cell number in fetal lungs through ROCK-Yap/Taz pathway

Accurate fluid pressure in the fetal lung is critical for its development, especially at the beginning of the saccular stage when alveolar epithelial type 1 (AT1) and type 2 (AT2) cells differentiate from the epithelial progenitors. Despite our growing understanding of the role of physical forces in lung development, the molecular mechanisms that regulate the transduction of mechanical stretch to alveolar differentiation remain elusive. To simulate lung distension, we optimized both an ex vivo model with precision cut lung slices and an in vivo model of fetal tracheal occlusion. Increased mechanical tension showed to improve alveolar maturation and differentiation toward AT1. By manipulating ROCK pathway, we demonstrate that stretch-induced Yap/Taz activation promotes alveolar differentiation toward AT1 phenotype via ROCK activity. Our findings show that balanced ROCK-Yap/Taz signaling is essential to regulate AT1 differentiation in response to mechanical stretching of the fetal lung, which might be helpful in improving lung development and regeneration.

Congenital diaphragmatic hernia: a single-centre experience at Kepler University Hospital Linz

Congenital diaphragmatic hernia (CDH) is found in about 1 of 3000 live births and is often complicated by pulmonary hypoplasia and alteration of the pulmonary arterial wall with resulting pulmonary hypertension. Since 2005, with the fusion of the children’s hospital and the maternity clinic of the Kepler University Hospital Linz, affected neonates have been treated according to a standard protocol at our perinatal centre. Some prenatally measured parameters have been used to predict mortality, e.g., observed-to-expected lung-to-head ratio or lung volume measurements by nuclear magnetic resonance imaging. We performed a retrospective chart review of 67 new-borns with CDH treated at our institution to detect any predictors of hospital mortality from parameters routinely collected within the first 24 h of life. The term “liver up” was identified as a predictor of hospital mortality; OR 9.2 (95% CI 1.9–51.1, p = 0.002, sensitivity 79%, specificity 71%). In addition, the need for application of high-frequency oscillatory ventilation during the first 24 h was associated with mortality; OR 44.4 (95% CI 6.3–412.1, p = 0.001, sensitivity 85.7%, specificity 88%).

Randomized Trial of Fetal Surgery for Moderate Left Diaphragmatic Hernia

BACKGROUND

Fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased postnatal survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data are lacking to inform its effects in infants with moderate disease.

METHODS

In this open-label trial conducted at many centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with a moderate isolated congenital diaphragmatic hernia on the left side to FETO at 30 to 32 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcomes were infant survival to discharge from a neonatal intensive care unit (NICU) and survival without oxygen supplementation at 6 months of age.

RESULTS

In an intention-to-treat analysis involving 196 women, 62 of 98 infants in the FETO group (63%) and 49 of 98 infants in the expectant care group (50%) survived to discharge (relative risk , 1.27; 95% confidence interval [CI], 0.99 to 1.63; two-sided P = 0.06). At 6 months of age, 53 of 98 infants (54%) in the FETO group and 43 of 98 infants (44%) in the expectant care group were alive without oxygen supplementation (relative risk, 1.23; 95% CI, 0.93 to 1.65). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (44% vs. 12%; relative risk, 3.79; 95% CI, 2.13 to 6.91), as was the incidence of preterm birth (64% vs. 22%, respectively; relative risk, 2.86; 95% CI, 1.94 to 4.34), but FETO was not associated with any other serious maternal complications. There were two spontaneous fetal deaths (one in each group) without obvious cause and one neonatal death that was associated with balloon removal.

CONCLUSIONS

This trial involving fetuses with moderate congenital diaphragmatic hernia on the left side did not show a significant benefit of FETO performed at 30 to 32 weeks of gestation over expectant care with respect to survival to discharge or the need for oxygen supplementation at 6 months. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT00763737.).

Randomized Trial of Fetal Surgery for Severe Left Diaphragmatic Hernia

BACKGROUND

Observational studies have shown that fetoscopic endoluminal tracheal occlusion (FETO) has been associated with increased survival among infants with severe pulmonary hypoplasia due to isolated congenital diaphragmatic hernia on the left side, but data from randomized trials are lacking.

METHODS

In this open-label trial conducted at centers with experience in FETO and other types of prenatal surgery, we randomly assigned, in a 1:1 ratio, women carrying singleton fetuses with severe isolated congenital diaphragmatic hernia on the left side to FETO at 27 to 29 weeks of gestation or expectant care. Both treatments were followed by standardized postnatal care. The primary outcome was infant survival to discharge from the neonatal intensive care unit. We used a group-sequential design with five prespecified interim analyses for superiority, with a maximum sample size of 116 women.

RESULTS

The trial was stopped early for efficacy after the third interim analysis. In an intention-to-treat analysis that included 80 women, 40% of infants (16 of 40) in the FETO group survived to discharge, as compared with 15% (6 of 40) in the expectant care group (relative risk, 2.67; 95% confidence interval [CI], 1.22 to 6.11; two-sided P = 0.009). Survival to 6 months of age was identical to the survival to discharge (relative risk, 2.67; 95% CI, 1.22 to 6.11). The incidence of preterm, prelabor rupture of membranes was higher among women in the FETO group than among those in the expectant care group (47% vs. 11%; relative risk, 4.51; 95% CI, 1.83 to 11.9), as was the incidence of preterm birth (75% vs. 29%; relative risk, 2.59; 95% CI, 1.59 to 4.52). One neonatal death occurred after emergency delivery for placental laceration from fetoscopic balloon removal, and one neonatal death occurred because of failed balloon removal. In an analysis that included 11 additional participants with data that were available after the trial was stopped, survival to discharge was 36% among infants in the FETO group and 14% among those in the expectant care group (relative risk, 2.65; 95% CI, 1.21 to 6.09).

CONCLUSIONS

In fetuses with isolated severe congenital diaphragmatic hernia on the left side, FETO performed at 27 to 29 weeks of gestation resulted in a significant benefit over expectant care with respect to survival to discharge, and this benefit was sustained to 6 months of age. FETO increased the risks of preterm, prelabor rupture of membranes and preterm birth. (Funded by the European Commission and others; TOTAL ClinicalTrials.gov number, NCT01240057.).

Impact of fetal endoscopic tracheal occlusion in fetuses with congenital diaphragmatic hernia and moderate lung hypoplasia

OBJECTIVE

To assess the effect of Fetal Endoscopic Tracheal Occlusion (FETO) on neonatal survival in fetuses with left congenital diaphragmatic hernia (CDH) and moderate lung hypoplasia.

STUDY DESIGN

CDH fetuses with moderate pulmonary hypoplasia (observed/expected lung area to head ratio between 26% and 35%, or between 36% and 45% with liver herniation) were prospectively recruited. Included patients were matched to a control group who were ineligible for FETO. Primary outcomes were survival at 28 days, at discharge, and at 6 months of age, respectively.

RESULTS

58 cases were recruited, 29 treated with FETO and 29 matched controls. Median gestational age (GA) at balloon placement and removal were 29.6 and 33.6 weeks, respectively. FETO group showed significantly lower GA at delivery (35.2 vs. 37.1 weeks, respectively, p < 0.01), higher survival at 28 days (51.7 vs. 24.1%, respectively, p = 0.03), at discharge (48.3 vs. 24.1%, respectively, p = 0.06), and at six months of age (41.4 vs. 24.1%, respectively, p = 0.16), and significantly lower length of ventilatory support (17.8 vs. 32.3 days, p = 0.01) and NICU stay (34.2 vs. 58.3 days, p = <0.01) compared to controls.

CONCLUSION

FETO was associated with a non-significant increase in survival and significantly lower neonatal respiratory morbidity among CDH fetuses with moderate lung hypoplasia.

New approaches to congenital diaphragmatic hernia

PURPOSE OF REVIEW

Congenital diaphragmatic hernia (CDH) is a structural birth defect that results in significant neonatal morbidity and mortality. CDH occurs in 2-4 per 10 000 pregnancies, and despite meaningful advances in neonatal intensive care, the mortality rate in infants with isolated CDH is still 25-30%. In this review, we will present data on the molecular underpinnings of pathological lung development in CDH, prenatal diagnosis, and prognostication in CDH cases, existing fetal therapy modalities, and future directions.

RECENT FINDINGS

Developments in the prenatal assessment and in-utero therapy of pregnancies complicated by congenital diaphragmatic hernia are rapidly evolving. Although ultrasound has been the mainstay of prenatal diagnosis, fetal MRI appears to be an increasingly important modality for severity classification. While fetal endoscopic tracheal occlusion (FETO) may have a role in the prenatal management of severe CDH cases, it is possible that future therapeutic paradigms will incorporate adjunct medical interventions with either stem cells or sildenafil in order to address the vascular effects of CDH on the developing lung.

SUMMARY

Both animal and human data have shown that the pathophysiological underpinnings of CDH are multifactorial, and it appears that future prenatal assessments and therapies will likely be as well.

Fetal endoscopic tracheal occlusion and pulmonary hypertension in moderate congenital diaphragmatic hernia

OBJECTIVE

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

Infants with moderate left-sided CDH according to O/E-LHR, FETO is associated with resolution of PH by the time of hospital discharge.

Fetal interventions for congenital renal anomalies

Congenital abnormalities of the kidney and urinary tract (CAKUT) represent 20% of prenatally diagnosed congenital abnormalities. Although the majority of these abnormalities do not require intervention either pre or postnatally, there is a subset of patients whose disease is so severe that it may warrant intervention prior to delivery to prevent morbidity and mortality. These cases consist of patients with moderate lower urinary tract obstruction (LUTO) in which vesicocentesis, shunting or cystoscopy are options and patients with early pregnancy renal anhydramnios (EPRA) in whom amnioinfusion therapy may be an option. The main causes of EPRA are congenital bilateral renal agenesis (CoBRA), cystic kidney disease (CKD) and severe LUTO. Untreated, EPRA is universally fatal secondary to anhydramnios induced pulmonary hypoplasia. The evidence regarding therapy for LUTO is limited and the stopped early PLUTO (Percutaneous Shunting in Lower Urinary Tract Obstruction) trial was unable to provide definitive answers about patient selection. Evidence for EPRA therapy is also scant. Serial amnioinfusions have shown promise in cases of EPRA due to CoBRA or renal failure and this treatment modality forms the basis of the ongoing NIH funded RAFT (Renal Anhydramnios Fetal Therapy) trial. At present, there is consensus that treatment for EPRA should only occur in the setting of a clinical trial.

Fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia: a narrative review of the history, current practice, and future directions

Fetal intervention for fetuses with congenital diaphragmatic hernia (CDH) has been investigated for over 30 years and is summarized in this manuscript. The review begins with a discussion of the history of fetal intervention for this severe congenital anomaly beginning with open fetal surgery with repair of the anatomical defect, shifting towards tracheal occlusion via open surgery techniques, and finally fetoscopic endoluminal balloon tracheal occlusion using a percutaneous approach. The current technique of fetal endoscopic tracheal occlusion (FETO) is described in detail with steps of the procedure and complementary figures. The main outcomes of single-institutional studies and multiple systematic reviews are examined and discussed. Despite these studies, the fetal community agrees that FETO remains investigational at this time as there is insufficient evidence to recommend it as the standard of care for CDH. A randomized controlled trial, The Tracheal Occlusion to Accelerate Lung Growth (TOTAL) trial, has been designed to attempt to answer this question in an elaborate, international, multi-institutional study and is described in the text. Finally, future directions of fetal intervention for antenatally diagnosed CDH are discussed, including options for non-isolated CDH, the Smart-TO balloon for nonoperative reversal of occlusion, and transplacental sildenafil for treatment of pulmonary hypertension prior to birth.

Reproducibility of Lung and Liver Volume Measurements on Fetal Magnetic Resonance Imaging in Left-Sided Congenital Diaphragmatic Hernia

INTRODUCTION

Congenital diaphragmatic hernia (CDH) affects 1 in 3,000 live births and is associated with significant morbidity and mortality.

METHODS

A review of fetal magnetic resonance imaging (MRI) examinations was performed for fetuses with left CDH and normal lung controls. Image review and manual tracings were performed by 4 pediatric radiologists; right and left lung volumes in the coronal and axial planes as well as liver volume above and below the diaphragm in the coronal plane were measured. Intra- and interreviewer reproducibility was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis.

RESULTS

Excellent intra- and interreviewer reproducibility of the right and left lung volume measurements was observed in both axial planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95-0.99; left lung: 0.97, 95% CI: 0.95-0.98) and coronal planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95-0.98; left lung: 0.96, 95% CI: 0.93-0.98). Moderate-to-good interreviewer reproducibility was observed for liver volume above the diaphragm (ICC 0.7, 95% CI: 0.59-0.81). Liver volume below the diaphragm had a good-to-excellent interreviewer reproducibility (ICC 0.88, 95% CI: 9.82-0.93).

CONCLUSIONS

The present study demonstrated an excellent intra- and interreviewer reproducibility of MRI lung volume measurements and good-to-moderate inter- and intrareviewer reproducibility of liver volume measurements after standardization of the methods at our fetal center.

Nanoparticles for delivery of agents to fetal lungs

Fetal treatment of congenital lung disease, such as cystic fibrosis, surfactant protein syndromes, and congenital diaphragmatic hernia, has been made possible by improvements in prenatal diagnostic and interventional technology. Delivery of therapeutic agents to fetal lungs in nanoparticles improves cellular uptake. The efficacy and safety of nanoparticle-based fetal lung therapy depends on targeting of necessary cell populations. This study aimed to determine the relative distribution of nanoparticles of a variety of compositions and sizes in the lungs of fetal mice delivered through intravenous and intra-amniotic routes. Intravenous delivery of particles was more effective than intra-amniotic delivery for epithelial, endothelial and hematopoietic cells in the fetal lung. The most effective targeting of lung tissue was with 250nm Poly-Amine-co-Ester (PACE) particles accumulating in 50% and 44% of epithelial and endothelial cells. This study demonstrated that route of delivery and particle composition impacts relative cellular uptake in fetal lung, which will inform future studies in particle-based fetal therapy.

Fetal endoscopic tracheal occlusion reverses the natural history of right-sided congenital diaphragmatic hernia: European multicenter experience

OBJECTIVE

To evaluate the neonatal outcome of fetuses with isolated right-sided congenital diaphragmatic hernia (iRCDH) based on prenatal severity indicators and antenatal management.

METHODS

This was a retrospective review of prospectively collected data on consecutive cases diagnosed with iRCDH before 30 weeks' gestation in four fetal therapy centers, between January 2008 and December 2018. Data on prenatal severity assessment, antenatal management and perinatal outcome were retrieved. Univariate and multivariate logistic regression analysis were used to identify predictors of survival at discharge and early neonatal morbidity.

RESULTS

Of 265 patients assessed during the study period, we excluded 40 (15%) who underwent termination of pregnancy, two cases of unexplained fetal death, two that were lost to follow-up, one for which antenatal assessment of lung hypoplasia was not available and six cases which were found to have major associated anomalies or syndromes after birth. Of the 214 fetuses with iRCDH included in the neonatal outcome analysis, 86 were managed expectantly during pregnancy and 128 underwent fetal endoscopic tracheal occlusion (FETO) with a balloon. In the expectant-management group, lung size measured by ultrasound or by magnetic resonance imaging was the only independent predictor of survival (observed-to-expected lung-to-head ratio (o/e-LHR) odds ratio (OR), 1.06 (95% CI, 1.02-1.11); P = 0.003). Until now, stratification for severe lung hypoplasia has been based on an o/e-LHR cut-off of 45%. In cases managed expectantly, the survival rate was 15% (4/27) in those with o/e-LHR ≤ 45% and 61% (36/59) for o/e-LHR > 45% (P = 0.001). However, the best o/e-LHR cut-off for the prediction of survival at discharge was 50%, with a sensitivity of 78% and specificity of 72%. In the expectantly managed group, survivors with severe pulmonary hypoplasia stayed longer in the neonatal intensive care unit than did those with mildly hypoplastic lungs. In fetuses with an o/e-LHR ≤ 45% treated with FETO, survival rate was higher than in those with similar lung size managed expectantly (49/120 (41%) vs 4/27 (15%); P = 0.014), despite higher prematurity rates (gestational age at birth: 34.4 ± 2.7 weeks vs 36.8 ± 3.0 weeks; P < 0.0001). In fetuses treated with FETO, gestational age at birth was the only predictor of survival (OR, 1.25 (95% CI, 1.04-1.50); P = 0.02).

CONCLUSIONS

Antenatal measurement of lung size can predict survival in iRCDH. In fetuses with severe lung hypoplasia, FETO was associated with a significant increase in survival without an associated increase in neonatal morbidity. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Safety and efficacy of smart tracheal occlusion device in diaphragmatic hernia lamb model

OBJECTIVE

To investigate the efficacy and safety of the 'smart' tracheal occlusion (Smart-TO) device in fetal lambs with diaphragmatic hernia (DH).

METHODS

DH was created in fetal lambs on gestational day 70 (term, 145 days). Fetuses were allocated to either pregnancy continuation until term (DH group) or fetoscopic endoluminal tracheal occlusion (TO), performed using the Smart-TO balloon on gestational day 97 (DH + TO group). On gestational day 116, the presence of the balloon was confirmed on ultrasound, then the ewe was walked around a 3.0-Tesla magnetic resonance scanner for balloon deflation, which was confirmed by ultrasound immediately afterwards. At term, euthanasia was performed and the fetus retrieved. Efficacy of occlusion was assessed by the lung-to-body-weight ratio (LBWR) and lung morphometry. Safety parameters included tracheal side effects assessed by morphometry and balloon location after deflation. The unoccluded DH lambs served as a comparator.

RESULTS

Six fetuses were included in the DH group and seven in the DH + TO group. All balloons deflated successfully and were expelled spontaneously from the airways. In the DH + TO group, in comparison to controls, the LBWR at birth was significantly higher (1.90 (interquartile range (IQR), 1.43-2.55) vs 1.07 (IQR, 0.93-1.46); P = 0.005), while on lung morphometry, the alveolar size was significantly increased (mean linear intercept, 47.5 (IQR, 45.6-48.1) vs 41.9 (IQR, 38.8-46.1) μm; P = 0.03); whereas airway complexity was lower (mean terminal bronchiolar density, 1.56 (IQR, 1.0-1.81) vs 2.23 (IQR, 2.14-2.40) br/mm² ; P = 0.005). Tracheal changes on histology were minimal in both groups, but more noticeable in fetal lambs that underwent TO than in unoccluded lambs (tracheal score, 2 (IQR, 1-3) vs 0 (0-1); P = 0.03).

CONCLUSIONS

In fetal lambs with DH, TO using the Smart-TO balloon is effective and safe. Occlusion can be reversed non-invasively and the deflated intact balloon expelled spontaneously from the fetal upper airways. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

NeoAPACHE II. Relationship Between Radiographic Pulmonary Area and Pulmonary Hypertension, Mortality, and Hernia Recurrence in Newborns With CDH

Congenital diaphragmatic hernia is a rare disease with high mortality and morbidity due to pulmonary hypoplasia and pulmonary hypertension. The aim of the study is to investigate the relationship between radiographic lung area and systolic pulmonary artery pressure (sPAP) on the first day of life, mortality, and hernia recurrence during the first year of life in infants with a congenital diaphragmatic hernia (CDH). A retrospective data collection was performed on 77 CDH newborns. Echocardiographic sPAP value, deaths, and recurrence cases were recorded. Lung area was calculated by tracing the lung's perimeter, excluding mediastinal structures, and herniated organs, on the preoperative chest X-ray performed within 24 h after birth. Logistic and linear regression analyses were performed. Deceased infants showed lower areas and higher sPAP values. One square centimeter of rising in the total, ipsilateral, and contralateral area was associated with a 22, 43, and 24% reduction in mortality risk. sPAP values showed a decreasing trend after birth, with a maximum of 1.84 mmHg reduction per unitary increment in the ipsilateral area at birth. Recurrence patients showed lower areas, with recurrence risk decreasing by 14 and 29% per unit increment of the total and ipsilateral area. In CDH patients, low lung area at birth reflects impaired lung development and defect size, being associated with increased sPAP values, mortality, and recurrence risk. Clinical Trial Registration: The manuscript is an exploratory secondary analysis of the trial registered at ClinicalTrials.gov with identifier NCT04396028.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a potentially severe anomaly that should be referred to a fetal care center with expertise in multidisciplinary evaluation and management. The pediatric radiologist plays an important role in the evaluation of CDH, both in terms of anatomical description of the anomaly and in providing detailed prognostic information for use in caring for the fetus and pregnant mother as well as planning for delivery and postnatal care. This article reviews the types of hernias, including distinguishing features and imaging clues. The most common methods of predicting severity are covered, and current fetal and postnatal therapies are explained. The author of this paper provides a handy reference for pediatric radiologists presented with a case of CDH as part of their daily practice.

Update on Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a rare developmental defect of the diaphragm, characterized by herniation of abdominal contents into the chest that results in varying degrees of pulmonary hypoplasia and pulmonary hypertension (PH). Significant advances in the prenatal diagnosis and identification of prognostic factors have resulted in the continued refinement of the approach to fetal therapies for CDH. Postnatally, protocolized approaches to lung-protective ventilation, nutrition, prevention of infection, and early aggressive management of PH have led to improved outcomes in infants with CDH. Advances in our understanding of the associated left ventricular (LV) hypoplasia and myocardial dysfunction in infants with severe CDH have allowed for the optimization of hemodynamics and management of PH. This article provides a comprehensive review of CDH for the anesthesiologist, focusing on the complex pathophysiology, advances in prenatal diagnosis, fetal interventions, and optimal postnatal management of CDH.

Current perspective and scope of fetal therapy: part 1

Fetal therapy term has been described for any therapeutic intervention either invasive or noninvasive for the purpose of correcting or treating any fetal malformation or condition. Fetal therapy is a rapidly evolving specialty and has gained pace in last two decades and now fetal intervention is being tried in many malformations with rate of success varying with the type of different fetal conditions. The advances in imaging techniques have allowed fetal medicine persons to make earlier and accurate diagnosis of numerous fetal anomalies. Still many fetal anomalies are managed postnatally because the fetal outcomes have not changed significantly with the use of fetal therapy and this approach avoids unnecessary maternal risk secondary to inutero intervention. The short-term maternal risk associated with fetal surgery includes preterm labor, premature rupture of membranes, uterine wall bleeding, chorioamniotic separation, placental abruption, chorioamnionitis, and anesthesia risk. Whereas, maternal long-term complications include risk of infertility, uterine rupture, and need for cesarean section in future pregnancies. The decision for invasive fetal therapy should be taken after discussion with parents about the various aspects like postnatal fetal outcome without fetal intervention, possible outcome if the fetal intervention is done, available postnatal intervention for the fetal condition, and possible short-term and long-term maternal complications. The center where fetal intervention is done should have facility of multi-disciplinary team to manage both maternal and fetal complications. The major issues in the development of fetal surgery include selection of patient for intervention, crafting effective fetal surgical skills, requirement of regular fetal and uterine monitoring, effective tocolysis, and minimizing fetal and maternal fetal risks. This review will cover the surgical or invasive aspect of fetal therapy with available evidence and will highlight the progress made in the management of fetal malformations in last two decades.

Sequential Minimally Invasive Fetal Interventions for Two Life-Threatening Conditions: A Novel Approach

INTRODUCTION

In utero interventions are performed in fetuses with "isolated" major congenital anomalies to improve neonatal outcomes and quality of life. Sequential in utero interventions to treat 2 anomalies in 1 fetus have not yet been described.

CASE PRESENTATION

Here, we report a fetus with a large left-sided intralobar bronchopulmonary sequestration (BPS) causing mediastinal shift, a small extralobar BPS, and concomitant severe left-sided congenital diaphragmatic hernia (CDH). At 26-week gestation, the BPS was noted to be increasing in size with a significant reduction in right lung volume and progression to fetal hydrops. The fetus underwent ultrasound-guided ablation of the BPS feeding vessel leading to complete tumor regression. However, lung development remained poor (O/E-LHR: 0.22) due to the left-sided CDH, prompting fetal endoscopic tracheal occlusion therapy at 28-week gestation to allow increased lung growth. After vaginal delivery, the newborn underwent diaphragmatic repair with resection of the extralobar sequestration. He was discharged home with tracheostomy on room air at 9 months.

DISCUSSION/CONCLUSION

Sequential in utero interventions to treat 2 severe major anomalies in the same fetus have not been previously described. This approach may be a useful alternative in select cases with otherwise high morbidity/mortality. Further studies are required to confirm our hypothesis.

Anatomical deadspace during resuscitation of infants with congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) has a high mortality and morbidity related to pulmonary hypoplasia.

AIMS

To test the hypothesis that CDH infants who survived would have a greater anatomical deadspace reflecting less severe pulmonary hypoplasia. Furthermore, infants with CDH who had undergone feto-tracheal occlusion (FETO) would have a greater anatomical deadspace.

STUDY DESIGN

Infants were studied during resuscitation in the delivery suite. They were all intubated immediately at delivery, given a neuromuscular blocking agent and underwent respiratory monitoring. The anatomical deadspace was calculated from volumetric capnography measurements.

SUBJECTS

Thirty infants born at 32 weeks of gestation or greater and diagnosed antenatally with a CDH were studied. Eleven had undergone FETO and overall five died.

OUTCOME MEASURES

Anatomical deadspace (Vd_ANA) and survival to discharge.

RESULTS

The median (IQR) gestational age of the infants was 38.1 (35.2-39.3) weeks and birthweight 2.8 (2.3-3.3) kg. The anatomical deadspace was higher in those infants who survived (2.9 (2.8-3.3) mls/kg) compared to those who died (2.2 (2.1-2.7) mls/kg; p = 0.003) and was higher in those who had undergone FETO (3.0 (2.8-3.8) mls/kg) compared to those who had not (2.8 (2.4-3.0) mls/kg; p = 0.032). In predicting survival to discharge, the anatomical deadspace had an AUC of 0.90 (p = 0.006).

CONCLUSIONS

CDH infants who survived had a larger anatomical deadspace than those who died suggesting they had less lung hypoplasia. In addition, infants who had undergone FETO had greater anatomical deadspace possibly reflecting distension of the conducting airways.

New device permitting non-invasive reversal of fetal endoscopic tracheal occlusion: ex-vivo and in-vivo study

OBJECTIVE

One of the drawbacks of fetal endoscopic tracheal occlusion (FETO) for congenital diaphragmatic hernia is the need for a second invasive intervention to re-establish airway patency. The 'Smart-TO' device is a new balloon for FETO that deflates spontaneously when placed in a strong magnetic field, therefore overcoming the need for a second procedure. The safety and efficacy of this device have not yet been demonstrated. The aim of this study was to investigate the reversibility, local side effects and occlusiveness of the Smart-TO balloon, both in a simulated in-utero environment and in the fetal lamb model.

METHODS

First, the reversibility of tracheal occlusion by the Smart-TO balloon was tested in a high-fidelity simulator. Following videoscopic tracheoscopic balloon insertion, the fetal mannequin was placed within a 1-L water-filled balloon to mimic the amniotic cavity. This was held by an operator in front of their abdomen, and different fetal and maternal positions were simulated to mimic the most common clinical scenarios. Following exposure to the magnetic field generated by a 1.5-T magnetic resonance (MR) machine, deflation of the Smart-TO balloon was assessed by tracheoscopy. In cases of failed deflation, the mannequin was reinserted into a water-filled balloon for additional MR exposure, up to a maximum of three times. Secondly, reversibility, occlusiveness and local effects of the Smart-TO balloon were tested in vivo in fetal lambs. Tracheal occlusion was performed in fetal lambs on gestational day 95 (term, 145 days), either using the balloon currently used in clinical practice (Goldbal2) (n = 5) or the Smart-TO balloon (n = 5). On gestational day 116, the presence of the balloon was assessed by tracheoscopy. Deflation was performed by puncture (Goldbal2) or MR exposure (Smart-TO). Six unoccluded fetal lambs served as controls. Following euthanasia, the lung-to-body-weight ratio (LBWR), lung morphometry and tracheal circumference were assessed. Local tracheal changes were measured using a hierarchical histologic scoring system.

RESULTS

Ex vivo, Smart-TO balloon deflation occurred after a single MR exposure in 100% of cases in a maternal standing position with the mannequin at a height of 95 cm (n = 32), 55 cm (n = 8) or 125 cm (n = 8), as well as when the maternal position was 'lying on a stretcher' (n = 8). Three out of eight (37.5%) balloons failed to deflate at first exposure when the maternal position was 'sitting in a wheelchair'. Of these, two balloons deflated after a second MR exposure, but one balloon remained inflated after a third exposure. In vivo, all Smart-TO balloons deflated successfully. The LBWR in fetal lambs with tracheal occlusion by a Smart-TO balloon was significantly higher than that in unoccluded controls, and was comparable with that in the Goldbal2 group. There were no differences in lung morphometry and tracheal circumference between the two balloon types. Tracheal histology showed minimal changes for both balloons.

CONCLUSIONS

In a simulated in-utero environment, the Smart-TO balloon was effectively deflated by exposure of the fetus in different positions to the magnetic field of a 1.5-T MR system. There was only one failure, which occurred when the mother was sitting in a wheelchair. In healthy fetal lambs, the Smart-TO balloon is as occlusive as the clinical standard Goldbal2 system and has only limited local side effects. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Feasibility and outcomes of fetoscopic endoluminal tracheal occlusion for severe congenital diaphragmatic hernia: A Japanese experience

AIM

To present the feasibility, safety and outcomes of fetoscopic endoluminal tracheal occlusion (FETO) for the treatment of severe congenital diaphragmatic hernia (CDH).

METHODS

This was a single-arm clinical trial of FETO for isolated left-sided CDH with liver herniation and Kitano Grade 3 stomach position (>50% stomach herniation into the right chest). FETO was performed at 27-29 weeks of gestation for cases with observed/expected lung to head ratio (o/e LHR) <25% and at 30-31 weeks for cases with o/e LHR ≥25%.

RESULTS

Eleven cases were enrolled between March 2014 and March 2016, and balloon insertion was successful in all cases. The median o/e LHR at entry was 27% (range, 20-33%). The median gestational age at FETO was 30.9 (range, 27.1-31.7) weeks. There were no severe maternal adverse events. One fetus died unexpectedly at 33 weeks of gestation due to cord strangulation by the detached amniotic membrane. There were 3 cases (27%) of preterm premature rupture of membranes. In all 10 cases, balloon removal at 34-35 weeks of gestation was successful. The median gestational age at delivery was 36.5 (range, 34.2-38.3) weeks. The median duration of occlusion and the median interval between balloon insertion and delivery were 26 days (range: 17-49 days) and 43 days (range, 21-66 days), respectively. Both the survival rate at 90 days of age and the rate of survival to discharge were 45% (5/11).

CONCLUSION

The FETO is feasible without maternal morbidity in Japan and could be offered to women whose fetuses show severe isolated left-sided CDH to accelerate fetal lung growth.

Single-Center Outcome of Fetoscopic Tracheal Balloon Occlusion for Severe Congenital Diaphragmatic Hernia

OBJECTIVE

To assess feasibility and maternal and infant outcome after fetoscopic tracheal balloon occlusion in patients with severe congenital diaphragmatic hernia.

METHODS

We conducted a prospective cohort study of fetuses with congenital diaphragmatic hernia and observed/expected lung/head ratio less than 30%. Eligible women had planned fetoscopic tracheal balloon occlusion at 26 0/7-29 6/7 weeks of gestation and balloon removal 4-6 weeks later. Standardized prenatal and postnatal care was at a single institution. Fetoscopic tracheal balloon occlusion details, lung growth, obstetric complications, birth outcome, and infant outcome details until discharge were evaluated.

RESULTS

Of 57 women screened, 14 (25%) were enrolled between 2015 and 2019. The congenital diaphragmatic hernia was left in 12 (86%); the pre-fetoscopic tracheal balloon occlusion observed/expected lung/head ratio was 23.2% (range 15.8-29.0%). At a median gestational age of 28 5/7 weeks (range 27 3/7-29 6/7), fetoscopic tracheal balloon occlusion was successful in all cases, and balloons remained in situ. Removal was elective in 10 (71%) patients, by ultrasound-guided needle puncture in eight (57%), and occurred at a median of 33 4/7 weeks of gestation (range 32 1/7-34 4/7; median occlusion 34 days, range 17-44). The post-fetoscopic tracheal balloon occlusion observed/expected lung/head ratio increased to a median of 62.8% (44.0-108) and fell to a median of 46.6% (range 30-92) after balloon removal (all Mann Whitney U, P<.003). For prevention of preterm birth, all patients received vaginal progesterone; 11 (79%) required additional tocolytics, three (21%) had vaginal pessary placement for cervical shortening, and five (36%) had amnioreduction for polyhydramnios. Median gestational age at birth was 39 2/7 weeks (range 33 6/7-39 4/7), with term birth in eight (57%) patients. Twelve (86%) neonates required high-frequency ventilation, and seven (50%) required extracorporeal membrane oxygenation for a median of 7 days (range 3-19). All neonates needed patch repair. Neonatal survival was 93% (n=13, 95% CI 49-100%), and survival to hospital discharge was 86% (n=12, 95% CI 44-100%).

CONCLUSION

Fetoscopic tracheal balloon occlusion for severe congenital diaphragmatic hernia was feasible in our single-center setting, with few obstetric complications and favorable infant outcome.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02710968.

Congenital diaphragmatic hernia: current management strategies from antenatal diagnosis to long-term follow-up

Congenital diaphragmatic hernia (CDH) is a developmental birth defect consisting of a diaphragmatic defect and abnormal lung development. CDH complicates 2.3-2.8 per 10,000 live births. Despite efforts to standardize clinical practice, management of CDH remains challenging. Frequent re-evaluation of clinical practices in CDH reveals that management of CDH is evolving from one of postnatal stabilization to prenatal optimization. Translational research reveals promising avenues for in utero therapeutic intervention, including fetoscopic endoluminal tracheal occlusion. These remain highly experimental and demand improved antenatal diagnostics. Timely diagnosis of CDH and identification of severely affected fetuses allow time for delivery planning or in utero therapeutics. Optimal perinatal care and surgical treatment strategies are highly debated. Improved CDH mortality rates have placed increased emphasis on identifying and monitoring the long-term sequelae of disease throughout childhood and into adulthood. We review the current management strategies for CDH, highlighting where progress has been made, and where future developments have the potential to revolutionize care in this vulnerable patient population.

The NeoAPACHE Study Protocol I: Assessment of the Radiographic Pulmonary Area and Long-Term Respiratory Function in Newborns With Congenital Diaphragmatic Hernia

In newborns with congenital diaphragmatic hernia (CDH), the radiographic lung area is correlated with functional residual capacity (FRC) and represents an alternative method to estimate lung hypoplasia. In a cohort of newborn CDH survivors, we retrospectively evaluated the relationship between radiographic lung area measured on the 1st day of life and long-term respiratory function. As a secondary analysis, we compared radiographic lung areas and respiratory function between patients undergoing fetal endoscopic tracheal occlusion (FETO) and patients managed expectantly (non-FETO). Total, ipsilateral, and contralateral radiographic areas were obtained by tracing lung perimeter as delineated by the diaphragm and rib cage, excluding mediastinal structures and herniated organs. Tidal volume (V_T), respiratory rate (RR), and their Z-Scores when compared to the norm were collected from pulmonary function tests (PFTs) performed at 12 ± 6 months of age. Linear regression analyses using the absolute Z-Score values for each parameter were performed. In CDH survivors, an increase in total and ipsilateral lung area measured at birth was related to a reduction in the absolute Z-Score for V_T in PFTs (p = 0.046 and p = 0.023, respectively), indicating a trend toward an improvement in pulmonary volumes and V_T normalization. Radiographic lung areas were not significantly different between FETO and non-FETO patients, suggesting a volumetric lung increase due to prenatal intervention. However, the mean Z-Score value for RR was significantly higher in the FETO group (p < 0.001), probably due to impaired diaphragmatic motility in the most severe cases. Further analyses are necessary to better characterize the role of the radiographic pulmonary area in the prognostic evaluation of respiratory function in patients with CDH. Clinical Trial Registration: This trial was registered at ClinicalTrials.gov with the identifier NCT04396028.

First steps in the development of a liquid biopsy in situ hybridization protocol to determine circular RNA biomarkers in rat biofluids

PURPOSE

Epigenetic factors are involved in the pathogenesis of congenital diaphragmatic hernia (CDH). Circular RNAs (circRNAs) are epigenetic regulators amenable to biomarker profiling. Here, we aimed to develop a liquid biopsy protocol to detect pathognomonic circRNA changes in biofluids.

METHODS

Our protocol is adapted from the existing BaseScope™ in situ hybridization technique. Rat biofluids were fixed in a gelatin-coated 96-well plate with formalin. Probes were designed to target circRNAs with significant fold change in nitrofen-induced CDH. FastRED fluorescence was assessed using a plate reader and confirmed with confocal microscopy. We tested maternal serum and amniotic fluid samples from control and nitrofen-treated rats.

RESULTS

We detected circRNAs in rat serum and amniotic fluid from control and CDH (nitrofen-treated) rats using fluorescent readout. CircRNA signal was observed in fixed biofluids as fluorescent punctate foci under confocal laser scanning microscopy. This was confirmed by comparison to BaseScope™ lung tissue sections. Signal was concentration dependent and DNase resistant.

CONCLUSION

We successfully adapted BaseScope™ to detect circRNAs in rat biofluids: serum and amniotic fluid. We detected signal from probes targeted to circRNAs that are dysregulated in rat CDH. This work establishes the preliminary feasibility of circRNA detection in prenatal diagnostics.

Antenatal sildenafil treatment improves neonatal pulmonary hemodynamics and gas exchange in lambs with diaphragmatic hernia

OBJECTIVES

Infants with congenital diaphragmatic hernia (CDH) are predisposed to pulmonary hypertension after birth, owing to lung hypoplasia that impairs fetal pulmonary vascular development. Antenatal sildenafil treatment attenuates abnormal pulmonary vascular and alveolar development in rabbit and rodent CDH models, but whether this translates to functional improvements after birth remains unknown. We aimed to evaluate the effect of antenatal sildenafil on neonatal pulmonary hemodynamics and lung function in lambs with diaphragmatic hernia (DH).

METHODS

DH was surgically induced at approximately 80 days' gestation in 16 lamb fetuses (term in lambs is approximately 147 days). From 105 days' gestation, ewes received either sildenafil (0.21 mg/kg/h intravenously) or saline infusion until delivery (n = 8 fetuses in each group). At approximately 138 days' gestation, all lambs were instrumented and then delivered via Cesarean section. The lambs were ventilated for 120 min with continuous recording of physiological (pulmonary and carotid artery blood flow and pressure; cerebral oxygenation) and ventilatory parameters, and regular assessment of arterial blood gas tensions. Only lambs that survived until delivery and with a confirmed diaphragmatic defect at postmortem examination were included in the analysis; these comprised six DH-sildenafil lambs and six DH-saline control lambs.

RESULTS

Lung-to-body-weight ratio (0.016 ± 0.001 vs 0.013 ± 0.001; P = 0.06) and dynamic lung compliance (0.8 ± 0.2 vs 0.7 ± 0.2 mL/cmH₂ O; P = 0.72) were similar in DH-sildenafil lambs and controls. Pulmonary vascular resistance decreased following lung aeration to a greater degree in DH-sildenafil lambs, and was 4-fold lower by 120 min after cord clamping than in controls (0.6 ± 0.1 vs 2.2 ± 0.6 mmHg/(mL/min); P = 0.002). Pulmonary arterial pressure was also lower (46 ± 2 vs 59 ± 2 mmHg; P = 0.048) and pulmonary blood flow higher (25 ± 3 vs 8 ± 2 mL/min/kg; P = 0.02) in DH-sildenafil than in DH-saline lambs at 120 min. Throughout the 120-min ventilation period, the partial pressure of arterial carbon dioxide tended to be lower in DH-sildenafil lambs than in controls (63 ± 8 vs 87 ± 8 mmHg; P = 0.057), and there was no significant difference in partial pressure of arterial oxygen between the two groups.

CONCLUSIONS

Sustained maternal antenatal sildenafil infusion reduced pulmonary arterial pressure and increased pulmonary blood flow in DH lambs for the first 120 min after birth. These findings of improved pulmonary vascular function are consistent with improved pulmonary vascular structure seen in two previous animal models. The data support the rationale for a clinical trial investigating the effect of antenatal sildenafil in reducing the risk of neonatal pulmonary hypertension in infants with CDH. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Anesthesia for predelivery procedures: ex-utero intrapartum treatment/intrauterine transfusion/surgery of the fetus

PURPOSE OF REVIEW

The aim of this study was to review the current literature on anesthesia for predelivery procedures and to summarize recent findings on anesthesiological methods used.

RECENT FINDINGS

Ex-utero intrapartum treatment (EXIT)-procedures are performed to secure the newborn's oxygenation in case of severe airway obstruction due to multiple conditions. A key feature of EXIT is continued intactness of the maternofetal circulation by uterine relaxation achieved by general anesthesia with high doses of anesthetic gases. A dose reduction may be achieved by combining inhaled anesthesia with propofol. After intrauterine transfusion the anesthesia team needs to be prepared for a potential need of emergency cesarean section. Temporary fetal endoluminal tracheal occlusion and laser coagulation for twin-to-twin transfusion syndrome may be either performed in monitored anesthesia care or neuraxial anesthesia. Neuraxial anesthesia also is a method of choice for fetal valvuloplasty and amniotic band release. Fetal myelomenigocele repair requires general anesthesia with tocolysis.

SUMMARY

Predelivery procedures require a differentiated anesthesia approach depending on the invasiveness of the intervention. Anesthesia ranges from monitored care to neuraxial anesthesia and general anesthesia. Depending on the procedure uterine relaxation and fetal immobilization are crucial for technical success. Interdisciplinary consultation optimizes the anesthesia plan for complex procedures.

Three-dimensional reconstruction of defects in congenital diaphragmatic hernia: a fetal MRI study

OBJECTIVE

To assess the clinical feasibility and validity of fetal magnetic resonance imaging (MRI)-based three-dimensional (3D) reconstruction to locate, classify and quantify diaphragmatic defects in congenital diaphragmatic hernia (CDH).

METHODS

This retrospective study included 46 cases of CDH which underwent a total of 69 fetal MRI scans (65 in-vivo and four postmortem) at the Medical University of Vienna during the period 1 January 2002 to 1 January 2017. Scans were performed between 16 and 38 gestational weeks using steady-state free precession, T2-weighted and T1-weighted sequences. MRI data were retrieved from the hospital database and manual segmentation of the diaphragm was performed with the open-source software, ITK-SNAP. The resulting 3D models of the fetal diaphragm and its defect(s) were validated by postmortem MRI segmentation and/or comparison of 3D model-based classification of the defect with a reference classification based on autopsy and/or surgery reports. Surface areas of the intact diaphragm and of the defect were measured and used to calculate defect-diaphragmatic ratios (DDR). The need for prosthetic patch repair and, in cases with repeated in-vivo fetal MRI scans, diaphragm growth dynamics, were analyzed based on DDR.

RESULTS

Fetal MRI-based manual segmentation of the diaphragm in CDH was feasible for all 65 (100%) of the in-vivo fetal MRI scans. Based on the 3D diaphragmatic models, one bilateral and 45 unilateral defects (n = 47) were further classified as posterolateral (23/47, 48.9%), lateral (7/47, 14.9%) or hemidiaphragmatic (17/47, 36.2%) defects, and none (0%) was classified as anterolateral. This classification of defect location was correct in all 37 (100%) of the cases in which this information could be verified. Nineteen cases had a follow-up fetal MRI scan; in five (26.3%) of these, the initial CDH classification was altered by the results of the second scan. Thirty-three fetuses underwent postnatal diaphragmatic surgical repair; 20 fetuses (all of those with DDR ≥ 54 and 88% of those with DDR > 30) received a diaphragmatic patch, while the other 13 underwent primary surgical repair. Individual DDRs at initial and at follow-up in-vivo fetal MRI correlated significantly (P < 0.001).

CONCLUSIONS

MRI-based 3D reconstruction of the fetal diaphragm in CDH has been validated to visualize, locate, classify and quantify the defect. Planning of postnatal surgery may be optimized by MRI-based prediction of the necessity for patch placement and the ability to personalize patch design based on 3D-printable templates. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Surgery

Fetal surgery is an established but still rapidly evolving specialty, born from the rationale that destructive embryologic processes, recognized early in gestation, can be curtailed by prenatal correction. As more and more centers begin offering fetal interventions, quality of care must be verified through transparency about clinical capabilities and resources. Level designations should be assigned based on capability, as in trauma and neonatal ICU centers for excellence, and volume requirements must be set for fetal surgery certification. Regionalization of this specialty care may be required to optimize outcomes.