Randomized Trial of Fetal Surgery for Severe Left Diaphragmatic Hernia

Minimally Invasive Fetal Surgery and the Next Frontier

Most patients with congenital anomalies do not require prenatal intervention. Furthermore, many congenital anomalies requiring surgical intervention are treated adequately after birth. However, there is a subset of patients with congenital anomalies who will die before birth, shortly after birth, or experience severe postnatal complications without fetal surgery. Fetal surgery is unique in that an operation is performed on the fetus as well as the pregnant woman who does not receive any direct benefit from the surgery but rather lends herself to risks, such as hemorrhage, abruption, and preterm labor. The maternal risks involved with fetal surgery have limited the extent to which fetal interventions may be performed but have, in turn, led to technical innovations that have significantly advanced the field. This review will examine congenital abnormalities that can be treated with minimally invasive fetal surgery and introduce the next frontier of prenatal management of fetal surgical pathology.

Respiratory support strategies in the prevention and treatment of bronchopulmonary dysplasia

Neonates who are born preterm frequently have inadequate lung development to support independent breathing and will need respiratory support. The underdeveloped lung is also particularly susceptible to lung injury, especially during the first weeks of life. Consequently, respiratory support strategies in the early stages of premature lung disease focus on minimizing alveolar damage. As infants grow and lung disease progresses, it becomes necessary to shift respiratory support to a strategy targeting the often severe pulmonary heterogeneity and obstructive respiratory physiology. With appropriate management, time, and growth, even those children with the most extreme prematurity and severe lung disease can be expected to wean from respiratory support.

Fetoscopic endoluminal tracheal occlusion (FETO) and bilateral congenital diaphragmatic hernia

Objectives

Bilateral congenital diaphragmatic hernias (CDH) occur in one to two percent of CDH patients. There is a lower survival due to the greater likelihood of lung hypoplasia and associated anomalies. We report an infant with bilateral CDH and duodenal atresia who was successfully treated by fetoscopic endoluminal tracheal occlusion (FETO).

Case presentation

The fetus was diagnosed with CDH at 23 weeks of gestation. Her mother was referred to our tertiary centre as the observed to expected lung-to-head ratio (O/E LHR) at 26 weeks of gestation was only 17 %. The fetus was treated by FETO with an increase in the LHR. The mother had polyhydramnios and underwent amniotic fluid drainage at 26 and 31 weeks of gestation. She had preterm, premature rupture of the membranes at 31+3 weeks of gestation. The FETO balloon was punctured and the mother received corticosteroids. She underwent spontaneous labour at 35+6 weeks of gestation when the LHR was 55 %. At birth, the female infant was electively intubated and ventilated. After successful stabilisation, surgical intervention was undertaken on day six when the defects were identified as bilateral, type C posterolateral CDHs. Bilateral patch repair of the CDHs was undertaken using 'domed' Goretex patches. Type one duodenal atresia (DA) was identified and repaired with enterotomy and diamond duodenoduodenostomy. There was partial and then full abdominal closure on days 12 and 15 respectively. The infant is now four months of age and requires no respiratory support.

Conclusions

FETO can improve prognosis in infants with bilateral CDH.

Congenital diaphragmatic hernia survival in an English regional ECMO center

Introduction

Congenital diaphragmatic hernia (CDH) remains a cause of neonatal death. Our aims are to describe contemporary rates of survival and the variables associated with this outcome, contrasting these with our study of two decades earlier and recent reports.

Materials and methods

A retrospective review of all infants diagnosed in a regional center between January 2000 and December 2020 was performed. The outcome of interest was survival. Possible explanatory variables included side of defect, use of complex ventilatory or hemodynamic strategies (inhaled nitric oxide (iNO), high-frequency oscillatory ventilation (HFOV), extracorporeal membrane oxygenation (ECMO), and Prostin), presence of antenatal diagnosis, associated anomalies, birth weight, and gestation. Temporal changes were studied by measuring outcomes in each of four consecutive 63-month periods.

Results

A total of 225 cases were diagnosed. Survival was 60% (134 of 225). Postnatal survival was 68% (134 of 198 liveborn), and postrepair survival was 84% (134 of 159 who survived to repair). Diagnosis was made antenatally in 66% of cases. Variables associated with mortality were the need for complex ventilatory strategies (iNO, HFOV, Prostin, and ECMO), antenatal diagnosis, right-sided defects, use of patch repair, associated anomalies, birth weight, and gestation. Survival has improved from our report of a prior decade and did not vary during the study period. Postnatal survival has improved despite fewer terminations. On multivariate analysis, the need for complex ventilation was the strongest predictor of death (OR=50, 95% CI 13 to 224, p<0.0001), and associated anomalies ceased to be predictive.

Conclusions

Survival has improved from our earlier report, despite reduced numbers of terminations. This may be related to increased use of complex ventilatory strategies.

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.

Termination of pregnancy after a prenatal diagnosis of congenital diaphragmatic hernia: Factors influencing the parental decision process

OBJECTIVE

To evaluate the incidence of termination of pregnancies (TOP) and factors associated with the decision for TOP in prenatally detected congenital diaphragmatic hernia (CDH).

STUDY DESIGN

Single-centre retrospective cohort includes all prenatally detected CDH cases born between January 2009 and December 2021. Parental factors, such as parity, and fetal characteristics, such as disease severity, were collected. Descriptive statistics were used to present the data. Differences between terminated and continued pregnancies were analysed.

RESULTS

The study population consisted of 278 prenatally detected CDH cases of which 80% detected <24 weeks of gestation. The TOP rate was 28% in cases that were detected <24 weeks of gestation. Twenty continued pregnancies resulted in either intrauterine fetal demise (n = 6), preterm birth <24 weeks (n = 2), or comfort care after birth (n = 12). The survival rate was 70% in the remaining 195 live born cases. Factors associated with the decision for TOP were additional fetal genetic or anatomical abnormalities (p < 0.0001) and expected severity of pulmonary hypoplasia in left-sided CDH (p = 0.0456).

CONCLUSION

The decision to terminate a pregnancy complicated by fetal CDH depends on the severity of pulmonary hypoplasia and the presence of additional abnormalities. This emphasises the importance of early referral to expertise centres for detailed evaluation and multidisciplinary counselling.

Lifesaving Treatments for the Tiniest Patients-A Narrative Description of Old and New Minimally Invasive Approaches in the Arena of Fetal Surgery

Fetal surgery has become a lifesaving reality for hundreds of fetuses each year. The development of a formidable spectrum of safe and effective minimally invasive techniques for fetal interventions since the early 1990s until today has led to an increasing acceptance of novel procedures by both patients and health care providers. From his vast personal experience of more than 20 years as one of the pioneers at the forefront of clinical minimally invasive fetal surgery, the author describes and comments on old and new minimally invasive approaches, highlighting their lifesaving or quality-of-life-improving potential. He provides easy-to-use practical information on how to perform partial amniotic carbon dioxide insufflation (PACI), how to assess lung function in fetuses with pulmonary hypoplasia, how to deal with giant CPAMS, how to insert shunts into fetuses with LUTO and hydrothorax when conventional devices are not available, and how to resuscitate a fetus during fetal cardiac intervention. Furthermore, the author proposes a curriculum for future fetal surgeons, solicits for the centralization of patients, for adequate maternal counseling, for adequate pain management and adequate hygienic conditions during interventions, and last but not least for starting the process of academic recognition of the matured field as an independent specialty. These steps will allow more affected expectant women and their unborn children to gain access to modern minimally invasive fetal surgery and therapy. The opportunity to treat more patients at dedicated centers will also result in more opportunities for the research of rare diseases and conditions, promising even better pre- and postnatal care in the future.

The effect of tracheal occlusion in congenital diaphragmatic hernia in the nitrofen rat lung explant model

PURPOSE

Here, we establish a tracheal occlusion (TO) model with rat lung explants in nitrofen-induced pulmonary hypoplasia in the congenital diaphragmatic hernia (CDH).

METHODS

We extracted lungs from rats on an embryonic day 18. We mimicked TO in the lung explants by tying the trachea. We assessed lung weight, morphometry, and abundance of Ki-67, Active caspase-3, and Prosurfactant Protein C (proSP-C) with immunofluorescence.

RESULTS

Lung weight was higher in TO + than TO - on day 1. Abundance of Ki-67 was higher in TO + than TO - (0.15 vs. 0.32, p = 0.009 for day 1, 0.07 vs. 0.17, p = 0.004 for day 2, 0.07 vs. 0.12, p = 0.044 for day 3), and Active caspase-3 was higher in TO + than TO - on day 2 and day 3 (0.04 vs. 0.03 p = 0.669 for day 1, 0.03 vs. 0.13 p < 0.001 for day 2, 0.04 vs. 0.17 p = 0.008 for day3). However, proSP-C protein abundance was lower in TO + than TO - (67.9 vs. 59.1 p = 0.033 for day 1, 73.5 vs. 51.6 p = 0.038 for day 2, 83.1 vs. 56.4 p = 0.009 for day 3).

CONCLUSIONS

The TO model in lung explants mimics the outcomes of current surgical models of TO and further studies can reveal the cellular and molecular effects of TO in CDH lungs.

International Society for Prenatal Diagnosis 2022 DEBATE: There should be formal accreditation and ongoing quality assurance/review for units offering fetal therapy that includes public reporting of outcomes

The field of fetal therapy has so far escaped from formal accreditation and quality control. Despite that, current published evidence shows that outcomes of interventions in younger fetal therapy centers are similar to what is achieved in more experienced centers and outcomes of interventions have improved over time. The question however remains what is not being published and what should be the standard of care, given the lack of level 1 evidence from randomized controlled trials for many interventions. Formal collaborative networks such as NAFTnet and others allow for anonymized benchmarking of center outcomes, without publicly shaming (and financially punishing) underperforming centers. Large registries also allow for tracking of rare complications and may result in improved patient outcomes over time. Core outcome sets, which could serve as a basis for outcome reporting, are available for some conditions, but certainly not for all, resulting in communication difficulties between centers. Formal accreditation, quality control, and outcome reporting are hard to implement, expensive, and may result in decreasing access to care by pushing smaller centers out of the market. Despite the existing difficulties, international societies have committed to quality improvement, and fetal therapy programs are strongly recommended to participate in voluntary outcome tracking.

In Utero Therapy for Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia is an anomaly that is often prenatally diagnosed and spans a wide spectrum of disease, with high morbidity and mortality associated with fetuses with severe defects. Congenital diaphragmatic hernia is thus an ideal target for fetal intervention. We review the literature on prenatal diagnosis, describe the history of fetal intervention for congenital diaphragmatic hernia, and discuss fetal endoscopic tracheal occlusion and the Tracheal Occlusion To Accelerate Lung growth trial results. Finally, we present preclinical studies for potential future directions.

Prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia: a systematic review and meta-analysis

PURPOSE

This study aimed to evaluate prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia (CDH).

METHODS

A systematic literature search was performed to identify relevant observational studies that evaluated the ability of lung-to-head ratio (LHR), observed-to-expected LHR (o/e-LHR), observed-to-expected total fetal lung volume (o/e-TFLV), lung-to-thorax transverse area ratio (L/T ratio), intrathoracic herniation of the liver and the stomach, and side of diaphragmatic hernia, using a threshold for the prediction of mortality in fetuses with CDH. Study quality was assessed using the QUADAS-2 tool. Hierarchical summary receiver operating characteristic curves were constructed.

RESULTS

A total of 50 articles were included in this meta-analysis. The QUADAS-2 tool identified a high risk of bias in more than one domain scored in all parameters. Among those parameters, the diagnostic odds ratio of mortality with o/e-LHR < 25%, o/e-TFLV < 25%, and L/T ratio < 0.08 were 11.98 [95% confidence interval (CI) 4.65-30.89], 11.14 (95% CI 5.19-23.89), and 10.28 (95% CI 3.38-31.31), respectively. The predictive values for mortality were similar between the presence of liver herniation and retrocardiac fetal stomach position.

CONCLUSIONS

This systematic review suggests that o/e-LHR, o/e-TFLV, and L/T ratio are equally good predictors of neonatal mortality in fetuses with isolated CDH.

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.

Expanding neonatal ECMO criteria: When is the premature neonate too premature

Extracorporeal membrane oxygenation (ECMO) is a universally accepted and life-saving therapy for neonates with respiratory or cardiac failure that is refractory to maximal medical management. Early studies found unacceptable risks of mortality and morbidities such as intracranial hemorrhage among premature and low birthweight neonates, leading to widely accepted ECMO inclusion criteria of gestational age ≥34 weeks and birthweight >2 kg. Although contemporary data is lacking, the most recent literature demonstrates increased survival and decreased rates of intracranial hemorrhage in premature neonates who are supported with ECMO. As such, it seems like the right time to push the boundaries of ECMO on a case-by-case basis beginning with neonates 32-34 weeks GA in large volume centers with careful neurodevelopmental follow-up to better inform practices changes on this select population.

Changing populations being treated with ECMO in the neonatal period - who are the others?

Extracorporeal life support via extracorporeal membrane oxygenation (ECMO) has served the sickest of neonates for almost 50 years. Naturally, the characteristics of neonates receiving ECMO have changed. Advances in care have averted the need for ECMO for some, while complex cases with uncertain outcomes, previously not eligible for ECMO, are now considered. Characterizing the disease states and outcomes for neonates on ECMO is challenging as many infants do not fall into classic categories, i.e. meconium aspiration syndrome (MAS), respiratory distress syndrome (RDS), or congenital diaphragmatic hernia (CDH). Since 2017, over one third of neonatal respiratory ECMO runs reported to the Extracorporeal Life Support Organization Registry are grouped as Other, a catch-all that encompasses those with a diagnosis not included in the classic categories. This review summarizes the historical neonatal ECMO population, reviews advances in therapy and technology impacting neonatal care, and addresses the unknowns in the ever-growing category of Other.

Ventilation-to-perfusion relationships and right-to-left shunt during neonatal intensive care in infants with congenital diaphragmatic hernia

BACKGROUND

We aimed to explore the postnatal evolution of ventilation/perfusion ratio (VA/Q) and right-to-left shunt in infants with congenital diaphragmatic hernia (CDH) and whether these indices predicted survival to discharge.

METHODS

Retrospective cohort study at King's College Hospital, London, UK of infants admitted with CDH in 10 years (2011-2021). The non-invasive method of the oxyhaemoglobin dissociation curve was used to determine the VA/Q and shunt in the first 24 h of life, pre-operation, pre-extubation and in the deceased infants, before death.

RESULTS

Eighty-two infants with CDH (71 left-sided) were included with a median (IQR) gestation of 38.1(34.8-39.0) weeks. Fifty-three (65%) survived to discharge from neonatal care. The median (IQR) VA/Q in the first 24 h was lower in the deceased infants [0.09(0.07-0.12)] compared to the ones who survived [0.28(0.19-0.38), p < 0.001]. In the infants who survived, the VA/Q was lower in the first 24 h [0.28 (0.19-0.38)] compared to pre-operation [0.41 (0.3-0.49), p < 0.001] and lower pre-operation compared to pre-extubation [0.48 (0.39-0.55), p = 0.027]. The shunt was not different in infants who survived compared to the infants who did not.

CONCLUSIONS

Ventilation-to-perfusion ratio was lower in infants who died in the neonatal period compared to the ones that survived and improved in surviving infants over the immediate postnatal period.

IMPACT

The non-invasive method of the oxyhaemoglobin dissociation curve was used to determine the ventilation/perfusion ratio VA/Q in infants with congenital diaphragmatic hernia (CDH) in the first 24 h of life, pre-operation, pre-extubation and in the deceased infants, before death. The VA/Q in the first 24 h of life was lower in the infants who did not survive to discharge from neonatal care compared to the ones who survived. In the infants who survived, the VA/Q improved over the immediate postnatal period. The non-invasive calculation of VA/Q can provide valuable information relating to survival to discharge.

Special considerations in randomized trials investigating neonatal surgical treatments

Randomized controlled trials (RCTs) are challenging, but are the studies most likely to change practice and benefit patients. RCTs investigating neonatal surgical therapies are rare. The Necrotizing Enterocolitis Surgery Trial (NEST) was the first surgical RCT conducted by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neonatal Research Network (NRN), and multiple lessons were learned. NEST was conducted over a 7.25-year enrollment period and the primary outcome was death or neurodevelopmental impairment (NDI) at 18-22 months corrected age. Surgical investigators designing clinical trials involving neonatal surgical treatments have many considerations to include, including how to study eligible but non-randomized patients, heterogeneity of treatment effect, use of frequentist and Bayesian analyses, assessment of generalizability, and anticipating criticisms during peer review. Surgeons are encouraged to embrace these challenges and seek innovative methods to acquire evidence that will be used to improve patient outcomes.

Treatment with Amniotic Fluid Stem Cell Extracellular Vesicles Promotes Fetal Lung Branching and Cell Differentiation at Canalicular and Saccular Stages in Experimental Pulmonary Hypoplasia Secondary to Congenital Diaphragmatic Hernia

Pulmonary hypoplasia secondary to congenital diaphragmatic hernia (CDH) is characterized by impaired branching morphogenesis and differentiation. We have previously demonstrated that administration of extracellular vesicles derived from rat amniotic fluid stem cells (AFSC-EVs) rescues development of hypoplastic lungs at the pseudoglandular and alveolar stages in rodent models of CDH. Herein, we tested whether AFSC-EVs exert their regenerative effects at the canalicular and saccular stages, as these are translationally relevant for clinical intervention. To induce fetal pulmonary hypoplasia, we gavaged rat dams with nitrofen at embryonic day 9.5 and demonstrated that nitrofen-exposed lungs had impaired branching morphogenesis, dysregulated signaling pathways relevant to lung development (FGF10/FGFR2, ROBO/SLIT, Ephrin, Neuropilin 1, β-catenin) and impaired epithelial and mesenchymal cell marker expression at both stages. AFSC-EVs administered to nitrofen-exposed lung explants rescued airspace density and increased the expression levels of key factors responsible for branching morphogenesis. Moreover, AFSC-EVs rescued the expression of alveolar type 1 and 2 cell markers at both canalicular and saccular stages and restored markers of club, ciliated epithelial, and pulmonary neuroendocrine cells at the saccular stage. AFSC-EV-treated lungs also had restored markers of lipofibroblasts and PDGFRA+ cells to control levels at both stages. EV tracking showed uptake of AFSC-EV RNA cargo throughout the fetal lung and an mRNA-miRNA network analysis identified that several miRNAs responsible for regulating lung development processes were contained in the AFSC-EV cargo. These findings suggest that AFSC-EV-based therapies hold potential for restoring fetal lung growth and maturation in babies with pulmonary hypoplasia secondary to CDH.

Minimally Invasive Bimanual Fetal Surgery—A Review

Background: The aim of this review is to discuss experimental and clinical techniques and interventions of fetal surgery which have been performed minimally invasively by the means of a three-port approach for the fetoscope and instruments for the left and right hand of the surgeon (bimanual minimally invasive fetal surgery). Methods: a print and electronic literature search was performed; the titles and abstracts were screened and included reports were reviewed in a two-step approach. First, reports other than minimally invasive fetal surgery were excluded, then a full text review and analysis of the reported data was performed. Results: 17 reports were included. The heterogeneity of the included reports was high. Although reports on human fetoscopic surgical procedures can be found, most of them do not pick out bimanual fetal surgery as a central theme but rather address interventions applying a fetoscope with a working channel for a laser fiber, needle or flexible instrument. Most reports were on experimentation in animal models, the human application of minimally invasive fetoscopic bimanual surgery is rare and has at best been explored for the prenatal treatment of spina bifida. Some reported bimanual fetoscopic procedures were performed on the exteriorized uterus via a maternal laparotomy and can therefore not be classified as being truly minimally invasive. Discussion: our results demonstrate that minimally invasive fetoscopic bimanual surgery is rare, even in animal models, excluding many other techniques and procedures that are loosely termed ‘minimally invasive fetal surgery’ which we suggest to better label as ‘interventions’. Thus, more research on percutaneous minimally invasive bimanual fetoscopic surgery is warranted, with the aim to reduce the maternal, uterine and fetal trauma for correction of congenital malformations.

Anesthesia for fetal operative procedures: A systematic review

Objective

The anesthetic management of fetal operative procedures (FOP) is a highly debated topic. Literature on fetal pain perception and response to external stimuli is rapidly expanding. Nonetheless, there is no consensus on the fetal consciousness nor on the instruments to measure pain levels. As a result, no guidelines or clinical recommendations on anesthesia modality during FOP are available. This systematic literature review aimed to collect the available knowledge on the most common fetal interventions, and summarize the reported outcomes for each anesthetic approach. Additional aim was to provide an overall evaluation of the most commonly used anesthetic agents.

Methods

Two systematic literature searches were performed in Embase, Medline, Web of Science Core Collection and Cochrane Central Register of Controlled Trials up to December 2021. To best cover the available evidence, one literature search was mostly focused on fetal surgical procedures; while anesthesia during FOP was the main target for the second search. The following fetal procedures were included: fetal transfusion, laser ablation of placental anastomosis, twin-reversed arterial perfusion treatment, fetoscopic endoluminal tracheal occlusion, thoraco-amniotic shunt, vesico-amniotic shunt, myelomeningocele repair, resection of sacrococcygeal teratoma, ligation of amniotic bands, balloon valvuloplasty/septoplasty, ex-utero intrapartum treatment, and ovarian cyst resection/aspiration. Yielded articles were screened against the same inclusion criteria. Studies reporting anesthesia details and procedures’ outcomes were considered. Descriptive statistical analysis was performed and findings were reported in a narrative manner.

Results

The literature searches yielded 1,679 articles, with 429 being selected for full-text evaluation. A total of 168 articles were included. Overall, no significant differences were found among procedures performed under maternal anesthesia or maternal-fetal anesthesia. Procedures requiring invasive fetal manipulation resulted to be more effective when performed under maternal anesthesia only. Based on the available data, a wide range of anesthetic agents are currently deployed and no consistency has been found neither between centers nor procedures.

Conclusions

This systematic review shows great variance in the anesthetic management during FOP. Further studies, systematically reporting intraoperative fetal monitoring and fetal hormonal responses to external stimuli, are necessary to identify the best anesthetic approach. Additional investigations on pain pathways and fetal pain perception are advisable.

Fetal endoscopic tracheal occlusion for moderate and severe congenital diaphragmatic hernia: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Fetoscopic endoluminal tracheal occlusion (FETO) is considered to increase survival among fetuses with congenital diaphragmatic hernia (CDH). Data from high-quality trials had been lacking until the largest randomized controlled trials (the TOTAL trials) were completed. This study aimed to elucidate the efficacy and safety of FETO for increasing the survival of fetuses with moderate or severe CDH.

METHODS

Relevant studies published before August 1st, 2021 were identified by searching PubMed, Cochrane Library and Web of Science. Only randomized controlled trials (RCTs) reporting patients who underwent FETO versus patients who received standard perinatal care were included in the analysis. The primary outcome was survival in the FETO and control groups. The secondary aim was to evaluate complications during pregnancy, such as premature rupture of membranes (PROM) and preterm delivery, and neonatal complications, including the need for supplemental oxygen at birth and discharge and pulmonary hypertension in the FETO and control groups. The Mantel-Haenszel random effects model was applied, and risk ratios (RRs) or odds ratios (ORs) were calculated.

RESULTS

Four RCTs were eligible for inclusion. The quality of these studies was high. The pooled estimate of survival for fetuses with moderate or severe CDH was higher in the FETO group than in the control group [odds ratio (OR), 3.43; 95% confidence interval (CI), 1.12-10.48; P = 0.03] with relatively strong evidence of between-study heterogeneity (I² = 66%). Subgroup analysis revealed that in the severe CDH group, the pooled estimates of neonatal survival were significantly higher in the FETO group than in the control group (OR, 6.57; 95% CI, 1.39-31.06; P = 0.02). However, in the moderate CDH group, the pooled results of neonatal survival were only slightly higher in the FETO group than in the control group (OR, 1.65; 95% CI, 0.93-2.91; P = 0.08) and the difference was not significant. The risks of PROM and preterm delivery were both higher in the FETO group. No significant difference was found for the need for supplemental oxygen at birth and discharge or in pulmonary hypertension between the FETO group and matched controls. A limitation is that we were unable to calculate the effect of the second intervention on prematurity, which would have been meaningful for evaluating the risk of FETO for PROM or preterm delivery.

CONCLUSION

FETO increases the survival rate in fetuses with moderate and severe CDH, especially in fetuses with severe CDH. However, FETO is associated with a higher risk of PROM and preterm delivery, and the optimal time of FETO should be carefully chosen.

Improved survival for infants with severe congenital diaphragmatic hernia

BACKGROUND

Survival for severe (observed to expected lung-head ratio (O:E LHR) < 25%) congenital diaphragmatic hernia (CDH) remains a challenge (15-25%). Management strategies have focused on fetal endoscopic tracheal occlusion (FETO) and/or extracorporeal membrane oxygenation therapy (ECMO) utilization.

OBJECTIVE(S)

Describe single center outcomes for infants with severe CDH.

STUDY DESIGN

Observational study of 13 severe CDH infants managed with ECMO, a protocolized DR algorithm, and early repair on ECMO with an innovative perioperative anticoagulation strategy.

RESULTS

13/140 (9.3%) infants met criteria and were managed with ECMO. 77% survived ECMO and 69% survived to discharge. 22% underwent tracheostomy. Median days on mechanical ventilation was 39 days (IQR 22:107.5) and length of stay 135 days (IQR 62.5:211.5). All infants received a gastrostomy tube (GT) and were discharged home on oxygen and pulmonary hypertension (PH) meds.

CONCLUSION

Survival for infants with severe CDH can be optimized with early aggressive intervention and protocolized algorithms (149).

Regenerative medicine: prenatal approaches

This two-paper Series focuses on recent advances and applications of regenerative medicine that could benefit paediatric patients. Innovations in genomic, stem-cell, and tissue-based technologies have created progress in disease modelling and new therapies for congenital and incurable paediatric diseases. Prenatal approaches present unique opportunities associated with substantial biotechnical, medical, and ethical obstacles. Maternal plasma fetal DNA analysis is increasingly adopted as a noninvasive prenatal screening or diagnostic test for chromosomal and monogenic disorders. The molecular basis for cell-free DNA detection stimulated the development of circulating tumour DNA testing for adult cancers. In-utero stem-cell, gene, gene-modified cell (and to a lesser extent, tissue-based) therapies have shown early clinical promise in a wide range of paediatric disorders. Fetal cells for postnatal treatment and artificial placenta for ex-utero fetal therapies are new frontiers in this exciting field.

Imaging in neonatal respiratory disease

The purpose of this review is to describe the current state of the art in clinical imaging for NICU patients, divided into major areas that correspond to likely phenotypes of neonatal respiratory disease: airway abnormalities, parenchymal disease, and pulmonary vascular disease. All common imaging modalities (ultrasound, X-ray, CT, and MRI) are discussed, with an emphasis on modalities that are most relevant to the individual underlying aspects of disease. Some promising aspects of dynamic and functional imaging are included, where there may be future clinical applicability.

Trend and causes of maternal death, stillbirth and neonatal death over seven decades in Hong Kong

BACKGROUND

Reducing maternal and perinatal mortality is a global objective. Hong Kong is a city with low maternal and perinatal mortality but little is known about the trend and causes of these deaths in this high-income city. We analyzed the maternal death, stillbirth and neonatal death since 1946 in Hong Kong.

METHODS

Data were extracted from vital statistics, based on the number of registered deaths and births, provided by the Department of Health, the Government of the HKSAR. The annual change rate of mortality was evaluated by regression analysis. Contextual factors were collected to assess the association with mortality.

FINDINGS

Between 1946 and 2017, the stillbirth rate (per 1,000 total births) reduced from 21·5 to 2·4; early and late neonatal deaths (per 1,000 live births) reduced from 14·1 and 18·1 to 0·7 and 0·4 in 2017, respectively. The maternal mortality ratio (per 100,000 live births) declined from 125 to 1·8.The causes of maternal and perinatal deaths were available since 1981 and 1980 respectively. The leading causes of death were thromboembolism (37·0%) and obstetric haemorrhage (30·4%) for maternal death; congenital problem (30·1%) and prematurity (29·0%) for neonatal death. No data on causes of stillbirth were available. No specific shift of pattern was observed in the causes of maternal and neonatal death with time. There were no cases of maternal death due to sepsis and only 2 cases (2·2%) of maternal deaths due to indirect cause.

INTERPRETATION

The maternal and perinatal death have reduced significantly in Hong Kong and maintained at the lowest level globally. Indirect maternal death and sepsis were unusual causes of maternal deaths. Use of ICD-PM stillbirth classification, setting up a maternal death confidential enquiry and adding pregnancy checkbox could be the next step to identify and categorize hidden burden.

FUNDING

Nil.

Neonatal and fetal therapy of congenital diaphragmatic hernia-related pulmonary hypertension

Congenital diaphragmatic hernia (CDH) is a complex malformation characterised by a triad of pulmonary hypoplasia, pulmonary hypertension (PH) and cardiac ventricular dysfunction. Much of the mortality and morbidity in CDH is largely accounted for by PH, especially when persistent beyond the neonatal period and refractory to available treatment. Gentle ventilation, haemodynamic optimisation and pulmonary vasodilation constitute the foundations of neonatal treatment of CDH-related PH (CDH-PH). Moreover, early prenatal diagnosis, the ability to assess severity and the developmental nature of the condition generate the perfect rationale for fetal therapy. Shortcomings of currently available clinical therapies in combination with increased understanding of CDH pathophysiology have spurred experimental drug trials, exploring new therapeutic mechanisms to tackle CDH-PH. We herein discuss clinically available neonatal and fetal therapies specifically targeting CDH-PH and review the most promising experimental treatments and future research avenues.

The maternal-fetal transfer of passive immunity as a mechanism of transplacental nanoparticle drug delivery for prenatal therapies

Nanoparticles administered into the maternal circulation and across the placenta are a potential clinical therapy to treat congenital diseases. The mechanism by which nanoparticles can safely cross the placenta for targeted drug delivery to the fetus remains poorly understood. We demonstrate that the maternal-fetal transfer of passive immunity through the neonatal Fc Receptor (FcRn) can induce the transplacental transfer of chitosan nanoparticles modifed with IgG antibodies (414 ± 27 nm). The transfer of FITC-tagged IgG-modified chitosan nanoparticles was 2.8 times higher (p = 0.0264) compared to similarly-sized unmodified chitosan nanoparticles (375 ± 17 nm). Co-administration of free IgG competitively diminished the transplacental transfer of IgG-modified nanoparticles, yet unmodified nanoparticles remained unaffected. Colocalization of the FcRn and the IgG-modified chitosan nanoparticles were observed with confocal microscopy. Barrier function before and after nanoparticle administration remained intact as determined by TEER (75-79 Ω cm²) and immmunofluorescence of ZO-1 tight junction proteins. The results provide insight into the clinical applications of nanoparticles for prenatal therapies using the mechanism of the maternal-fetal transfer of passive immunity.

Antenatal Assessment of the Prognosis of Congenital Diaphragmatic Hernia: Ethical Considerations and Impact for the Management

Congenital diaphragmatic hernia (CDH) is associated with abnormal pulmonary development, which is responsible for pulmonary hypoplasia with structural and functional abnormalities in pulmonary circulation, leading to the failure of the cardiorespiratory adaptation at birth. Despite improvement in treatment options and advances in neonatal care, mortality remains high, at close to 15 to 30%. Several risk factors of mortality and morbidities have been validated in fetuses with CDH. Antenatal assessment of lung volume is a reliable way to predict the severity of CDH. The two most commonly used measurements are the observed/expected lung to head ratio (LHRo/e) and the total pulmonary volume (TPV) on MRI. The estimation of total pulmonary volume (TPVo/e) by means of prenatal MRI remains the gold standard. In addition to LHR and TPV measurements, the position of the liver (up, in the thorax or down, in the abdomen) also plays a role in the prognostic evaluation. This prenatal prognostic evaluation can be used to select fetuses for antenatal surgery, consisting of fetoscopic endoluminal tracheal occlusion (FETO). The antenatal criteria of severe CDH with an ascended liver (LHRo/e or TPVo/e < 25%) are undoubtedly associated with a high risk of death or significant morbidity. However, despite the possibility of estimating the risk in antenatal care, it is difficult to determine what is in the child’s best interest, as there still are many uncertainties: (1) uncertainty about individual short-term prognosis; (2) uncertainty about long-term prognosis; and (3) uncertainty about the subsequent quality of life, especially when it is known that, with a similar degree of disability, a child’s quality of life varies from poor to good depending on multiple factors, including family support. Nevertheless, as the LHR decreases, the foreseeable “burden” becomes increasingly significant, and the expected benefit is increasingly unlikely. The legal and moral principle of the proportionality of medical procedures, as well as the prohibition of “unreasonable obstinacy” in all investigations or treatments undertaken, is necessary in these situations. However, the scientific and rational basis for assessing the long-term individual prognosis is limited to statistical data that do not adequately reflect individual risk. The risk of self-fulfilling prophecies should be kept in mind. The information given to parents must take this uncertainty into account when deciding on the treatment plan after birth.

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.

Pulmonary hypertension in congenital diaphragmatic hernia: ANTENATAL PREDICTION AND IMPACT ON NEONATAL MORTALITY

OBJECTIVE

To determine the prevalence of pulmonary hypertension(PAH) in left-sided congenital diaphragmatic hernia(CDH); how we could predict it; and how PAH contributed to the model for mortality prediction.

STUDY DESIGN

Retrospective analysis in three European centers. The primary outcome was the presence of PAH on postnatal day(d)1,7, and at discharge. Studied predictors of PAH were: observed/expected-lung/head-ratio(o/e LHR), liver-herniation, FETO, and gestational age(GA) at delivery. The combined effect of pre-and postnatal variables on mortality was modeled by Cox regression.

RESULTS

Of the 197 neonates, 56(28.4%) died. At d1, 67.5%(133/197) had PAH and 61.9% (101/163) by d7. Overall, 6.4% (9/141) had PAH at discharge.At d1, o/eLHR(OR 0.96) and FETO(OR 2.99) independently correlated to PAH(AUC:0.74). At d7, PAH significantly correlated only with the use of FETO (OR 3.9;AUC:0.65). None were significant for PAH at discharge.Combining the occurrence of PAH with antenatal biomarkers improved mortality prediction(p=0.02), in a model including o/eLHR(HR:0.94), FETO(HR:0.35), liver herniation(HR:16.78), and PAH(HR:15.95).

CONCLUSIONS

Antenatal prediction of PAH was only moderate. The postnatal occurrence of PAH further increases the risk of death. Whereas this may be used to counsel parents in the postnatal period, our study demonstrates there is a need to find more accurate antenatal predictors for PAH. This article is protected by copyright. All rights reserved.

Prenatal treprostinil reduces the pulmonary hypertension phenotype in the rat model of congenital diaphragmatic hernia

Background

Persistent pulmonary hypertension (PH) causes significant mortality and morbidity in infants with congenital diaphragmatic hernia (CDH). Since pulmonary vascular abnormalities in CDH develop early during foetal development, we hypothesized that prenatal maternal administration of treprostinil, through its anti-remodelling effect, would improve the PH-phenotype in the nitrofen rat model of CDH.

Methods

In a dose-finding study in normal, healthy pregnant rats, we demonstrated target-range foetal plasma treprostinil concentrations without signs of toxicity. Next, an efficacy study was performed assessing the effects of treprostinil administration at 900 and 1500ng/kg/min from gestational day (GD) 16 until term (GD 21) in CDH and control pups. Pulmonary vascular and airway morphometry, lung mechanics, and expression patterns of genes implicated in the prostaglandin vasoactive pathway were studied.

Findings

In rats maternal administration of 1500ng/kg/min treprostinil reached target foetal concentrations, with no detrimental maternal or foetal side-effects. Prenatal exposure to 900 and 1500 ng/kg/min treprostinil reduced the medial wall thickness (%MWT) (CDH·900, 38.5± 8·4%; CDH.1500, 40·2±9·7%; CDH, 46·6±8·2%; both p < 0·0001) in rat pups with CDH, however increased the %MWT in normal foetuses (C.T.900, 36·6±11·1%; C.T.1500, 36·9±9·3%; C.P., 26·9±6·2%; both p < 0·001). Pulmonary airway development, lung hypoplasia and pulmonary function were unaffected by drug exposure.

Interpretation

In pregnant rats maternally administered treprostinil crosses the placenta, attains foetal target concentrations, and is well tolerated by both mother and foetuses. This report shows a significant reduction of pulmonary arteriole muscularization with prenatal treprostinil in a nitrofen rat model, supporting the promise of this treatment approach for PH of CDH.

Funding

United Therapeutics Corporation provided treprostinil and financial support (ISS-2020-10879).

New challenges of fetal therapy in Japan

Aim

To review new challenges of fetal therapy in Japan after the establishment of four existing fetal therapies as standard prenatal care with National Health Insurance coverage over the past 20 years.

Methods

Reported studies and our current research activities related to four fetal therapies newly performed in Japan were reviewed.

Results

Fetoscopic endoluminal tracheal occlusion (FETO) for congenital diaphragmatic hernia (CDH) aims to occlude the trachea using a detachable balloon to promote lung growth. Following the recent successful completion of an international randomized controlled trial for CDH, in which we participated, FETO is offered for severe left CDH to perform balloon insertion at 27–29 weeks and removal at 34 weeks of gestation. Fetal cystoscopy (FC) for low urinary tract obstruction was introduced to overcome the demerits of vesicoamniotic shunting. FC may provide a proper diagnosis by visual observation of the urethra and physiological treatment of the posterior urethral valve. The effectiveness of open fetal surgery for myelomeningocele (MMC), direct surgery with laparotomy and hysterotomy, for ameliorating hindbrain herniation and the motor function was demonstrated, but it was also associated with substantial maternal and fetal risks. Fetal aortic valvuloplasty (FAV), ultrasound‐guided fetal aortic balloon dilation for critical aortic stenosis with evolving hypoplastic left heart syndrome may improve left heart development and maintain biventricular circulation. Feasibility and safety studies for FC, MMC open fetal surgery, and FAV are currently ongoing.

Conclusions

Clinical research on FETO, FC, MMC open fetal surgery, and FAV has proceeded with careful preparations in Japan.

Care Levels for Fetal Therapy Centers

Fetal therapies undertaken to improve fetal outcome or to optimize transition to neonate life often entail some level of maternal, fetal, or neonatal risk. A fetal therapy center needs access to resources to carry out such therapies and to manage maternal, fetal, and neonatal complications that might arise, either related to the therapy per se or as part of the underlying fetal or maternal condition. Accordingly, a fetal therapy center requires a dedicated operational infrastructure and necessary resources to allow for appropriate oversight and monitoring of clinical performance and to facilitate multidisciplinary collaboration between the relevant specialties. Three care levels for fetal therapy centers are proposed to match the anticipated care complexity, with appropriate resources to achieve an optimal outcome at an institutional and regional level. A level I fetal therapy center should be capable of offering fetal interventions that may be associated with obstetric risks of preterm birth or membrane rupture but that would be very unlikely to require maternal medical subspecialty or intensive care, with neonatal risks not exceeding those of moderate prematurity. A level II center should have the incremental capacity to provide maternal intensive care and to manage extreme neonatal prematurity. A level III therapy center should offer the full range of fetal interventions (including open fetal surgery) and be able manage any of the associated maternal complications and comorbidities, as well as have access to neonatal and pediatric surgical intervention including indicated surgery for neonates with congenital anomalies.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare birth defect characterized by incomplete closure of the diaphragm and herniation of fetal abdominal organs into the chest that results in pulmonary hypoplasia, postnatal pulmonary hypertension owing to vascular remodelling and cardiac dysfunction. The high mortality and morbidity rates associated with CDH are directly related to the severity of cardiopulmonary pathophysiology. Although the aetiology remains unknown, CDH has a polygenic origin in approximately one-third of cases. CDH is typically diagnosed with antenatal ultrasonography, which also aids in risk stratification, alongside fetal MRI and echocardiography. At specialized centres, prenatal management includes fetal endoscopic tracheal occlusion, which is a surgical intervention aimed at promoting lung growth in utero. Postnatal management focuses on cardiopulmonary stabilization and, in severe cases, can involve extracorporeal life support. Clinical practice guidelines continue to evolve owing to the rapidly changing landscape of therapeutic options, which include pulmonary hypertension management, ventilation strategies and surgical approaches. Survivors often have long-term, multisystem morbidities, including pulmonary dysfunction, gastroesophageal reflux, musculoskeletal deformities and neurodevelopmental impairment. Emerging research focuses on small RNA species as biomarkers of severity and regenerative medicine approaches to improve fetal lung development.

Perioperative pharmacological interventions for fetal immobilisation during fetal surgery and invasive procedures

BACKGROUND

Developments in ultrasound assessment of pregnancy has resulted in the increasing diagnosis of antenatal fetal issues. Many structural fetal conditions as well as complications associated with multiple pregnancies have the potential for in-utero treatment to improve both pregnancy and neonatal outcomes. Procedures such as laser ablation for twin-twin syndrome or cord occlusion for selective fetal termination require fetal immobilisation. Immobilisation of the fetus can occur through administration of medication to the mother or directly to the fetus. This improves procedural success and reduces the ongoing risk to the pregnancy. Evidence regarding the best medication and mode of delivery helps to ensure the optimal decision is made for both the mother and the fetus.

OBJECTIVES

To assess the effects of perioperative pharmacological interventions for fetal immobilisation during fetal surgery and invasive procedures on fetal, neonatal, and maternal outcomes.  SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (10 May 2021), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs (including published abstracts) which compared different classes of medication administered to the mother or fetus to allow in-utero procedures to be performed. We also included cluster-randomised trials but excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

We used the standard Cochrane Pregnancy and Childbirth methods for data collection and analysis. Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy.

MAIN RESULTS

One study with three trial reports met the inclusion criteria. This involved 54 women with a multiple pregnancy. The study was conducted in a tertiary European hospital maternal-fetal medicine unit and compared remifentanil to diazepam for fetal immobilisation and maternal sedation during fetoscopic surgery.   Low-certainty evidence suggested that remifentanil may reduce fetal movement more than diazepam for two outcomes of fetal movement, one of fetal immobilisation at 40 minutes using a visual analogue score (VAS) (where 0 = immobile and 100 = baseline mobility), and one of gross body and limb movements (score was absolute number of movements), both assessed by a sonographer evaluating a taped ultrasound sequence (mean difference (MD) -65.00, 95% confidence interval (CI) -69.38 to -60.62 and MD -10.00, 95% CI -11.62 to -8.38; 1 study, 50 women).  Surgeons may also report being more satisfied with the procedure when using remifentanil rather than diazepam (risk ratio (RR) 2.88, 95% CI 1.60 to 5.15; 1 study, 50 women; low-certainty evidence). However, maternal respiratory rate may decrease more during the surgical procedure with remifentanil compared with diazepam (MD -6.00, 95% CI -8.29 to -3.71; 1 study, 50 women; low-certainty evidence). Maternal sedation may also be worse with remifentanil compared with diazepam (RR 0.09, 95% CI 0.01 to 0.65; 1 study, 50 women; low-certainty evidence) measured using an observer assessment of alertness/sedation (where a score of < 4 equates to profound sedation and > 4 equates to insufficient sedation). Perinatal mortality and time taken to perform the procedure were not reported in the trial.  We prespecified 20 outcomes and planned to use GRADE for 6 of them, all other outcomes were not able to be reported against for the purpose of meta-analysis due to data not being provided or unable to be interpreted. We assessed the included study at low risk of selection bias (appropriate random sequence generation and allocation concealment), performance bias (blinding of participants and personnel), detection bias (outcome assessors were blinded), attrition bias (incomplete outcome data minimal), and reporting bias.  Our GRADE assessment for certainty of the evidence indicates that there is low certainty of the evidence.

AUTHORS' CONCLUSIONS

We were only able to include one study with a small number of women, from a single centre, a European tertiary hospital. This study was published in 2005 with an abstract of this trial published in 2004. This study evaluated two intravenous medications administered to the mother - remifentanil and diazepam. This study reported our prespecified primary outcome but only evaluated several of our secondary outcomes, which limited further assessment. Low-certainty evidence suggested that remifentanil may be better at reducing fetal movements and surgeons were more satisfied with the procedure. However, maternal sedation and depression of breathing may be worse with remifentanil.  Further high-quality RCTs assessing both fetal and maternal medications are required to evaluate their efficacy for fetal immobilisation as well as safety for both mother and fetus.

Challenges and Pitfalls: Performing Clinical Trials in Patients With Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a rare developmental defect of the lungs and diaphragm, with substantial morbidity and mortality. Although internationally established treatment guidelines have been developed, most recommendations are still expert opinions. Trials in patients with CDH, more in particular randomized controlled trials, are rare. Only three multicenter trials in patients with CDH have been completed, which focused on fetoscopic tracheal occlusion and ventilation mode. Another four are currently recruiting, two with a focus on perinatal transition and two on the treatment of pulmonary hypertension. Herein, we discuss major challenges and pitfalls when performing a clinical trial in infants with CDH. It is essential to select the correct intervention and dose, select the appropriate population of CDH patients, and also define a relevant endpoint that allows a realistic duration and sample size. New statistical approaches might increase the feasibility of randomized controlled trials in patients with CDH. One should also timely perform the trial when there is still equipoise. But above all, awareness of policymakers for the relevance of investigator-initiated trials is essential for future clinical research in this rare disease.

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.

High-intensity focused ultrasound for noninvasive fetal therapy

High-intensity focused ultrasound (HIFU) consists of an ultrasonic beam that is focused within the body to induce tissue necrosis through both heat energy and as a result of cavitation, which occurs without damaging any intervening tissues. Therefore, it is possible to cauterize and treat tumors without surgical invasion by administering HIFU irradiation from outside the body. This approach has been clinically applied in various fields in recent years, and fetal therapy is no exception, with several clinical applications reported, mainly in basic experiments. This review summarizes the recent basic and clinical findings focusing on fetal treatment with HIFU.

Novel Ventilation Strategies to Reduce Adverse Pulmonary Outcomes

Extremely preterm infants who must suddenly support their own gas exchange with lungs that are incompletely developed and lacking adequate amount of surfactant and antioxidant defenses are susceptible to lung injury. The decades-long quest to prevent bronchopulmonary dysplasia has had limited success, in part because of increasing survival of more immature infants. The process must begin in the delivery room with gentle assistance in establishing and maintaining adequate lung aeration, followed by noninvasive support and less invasive surfactant administration. Various modalities of invasive and noninvasive support have been used with varying degree of effect and are reviewed in this article.

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.

Sonographic pulmonary response after tracheal occlusion in fetuses with severe isolated congenital diaphragmatic hernia

PURPOSE

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%).

CONCLUSION

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.