Advances in prenatal diagnosis and treatment of congenital diaphragmatic hernia

Imaging Assessment of Prognostic Parameters in Cases of Isolated Congenital Diaphragmatic Hernia: Integrative Review

OBJECTIVE

 Antenatal recognition of severe cases of congenital diaphragmatic hernia (CDH) by ultrasound (US) and magnetic resonance imaging (MRI) may aid decisions regarding the indication of fetal endoscopic tracheal occlusion.

METHODS

 An integrative review was performed. Searches in MEDLINE and EMBASE used terms related to CDH, diagnosis, MRI, and US. The inclusion criteria were reviews and guidelines approaching US and MRI markers of severity of CDH published in English in the past 10 years.

RESULTS

 The search retrieved 712 studies, out of which 17 publications were included. The US parameters were stomach and liver positions, lung-to-head ratio (LHR), observed/expected LHR (o/e LHR), and quantitative lung index. The MRI parameters were total fetal lung volume (TFLV), observed/expected TFLV, relative fetal or percent predicted lung volumes, liver intrathoracic ratio, and modified McGoon index. None of the parameters was reported to be superior to the others.

CONCLUSION

 The most mentioned parameters were o/e LHR, LHR, liver position, o/e TFLV, and TFLV.

From non-invasive to invasive fetal therapy: A comprehensive review and current update

"Fetus as patient" indicates fundamental concept of fetal therapy. With advance in maternal serum analysis and fetal imaging, prenatal screening has become standard of care. Accurate diagnosis in early gestation allows intervention to reverse pathophysiology and delay progression immediately. Non-invasive, minimally invasive and invasive therapies demonstrate their therapeutic potential in certain diseases. Recently, stem cell and gene therapies have been developed to avoid irreversible impairment. To elevate efficacy of treatment modality, extensive studies should be conducted according to regulatory authority. Striking a balance between scientific and ethical integrity is essential, so long-term follow up should be arranged for protecting mother and fetus.

Impact of congenital diaphragmatic hernia on diaphragm muscle function in neonatal rats

Congenital diaphragmatic hernia (CDH) is characterized by incomplete partitioning of the thoracic and abdominal cavities by the diaphragm muscle (DIAm). The resulting in utero invasion of the abdominal viscera into the thoracic cavity leads to impaired fetal breathing movements, severe pulmonary hypoplasia, and pulmonary hypertension. We hypothesized that in a well-established rodent model of Nitrofen-induced CDH, DIAm isometric force generation, and DIAm fiber cross-sectional areas would be reduced compared with nonlesioned littermate and Control pups. In CDH and nonlesioned pups at embryonic day 21 or birth, DIAm isometric force responses to supramaximal field stimulation (200 mA, 0.5 ms duration pulses in 1-s duration trains at rates ranging from 10 to 100 Hz) was measured ex vivo. Further, DIAm fatigue was determined in response to 120 s of repetitive stimulation at 40 Hz in 330-ms duration trains repeated each second. The DIAm was then stretched to L_o, frozen, and fiber cross-sectional areas were measured in 10 μm transverse sections. In CDH pups, there was a marked reduction in DIAm-specific force and force following 120 s of fatiguing contraction. The cross-sectional area of DIAm fibers was also reduced in CDH pups compared with nonlesioned littermates and Control pups. These results show that CDH is associated with a dramatic weakening of the DIAm, which may contribute to poor survival despite various surgical efforts to repair the hernia and improve lung development.NEW & NOTEWORTHY There are notable respiratory deficits related to congenital diaphragmatic hernia (CDH), yet the contribution, if any, of frank diaphragm muscle weakness to CDH is unexplored. Here, we use the well-established Nitrofen teratogen model to induce CDH in rat pups, followed by diaphragm muscle contractility and morphological assessments. Our results show diaphragm muscle weakness in conjunction with reduced muscle fiber density and size, contributing to CDH morbidity.

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.

An omic approach to congenital diaphragmatic hernia: a pilot study of genomic, microRNA, and metabolomic profiling

INTRODUCTION

The omic approach can help identify a signature that can be potentially used as biomarkers in babies with congenital diaphragmatic hernia (CDH).

OBJECTIVES

To find a specific microRNA (miR) and metabolic fingerprint of the tracheal aspirates (TA) of CDH patients. We conducted a genetic analysis from blood samples.

METHODS

TA samples collected in the first 48 h of life in patients with CDH, compared with age-matched controls. Metabolomics done by a mass spectroscopy-based assay. Genomics done using chromosomal microarray analysis.

RESULTS

CDH (n = 17) and 16 control neonates enrolled. miR-16, miR-17, miR-18, miR-19b, and miR-20a had an increased expression, while miR-19a had a twofold decreased expression in CDH patients, compared with age-matched control patients. Specific metabolites separated neonates with CDH from controls. A genetic mutation found in a small subset of patients.

CONCLUSIONS

Specific patterns of metabolites and miR expression can be discerned in TA samples in infants with CDH.

Fetal intervention for congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a condition that results from incomplete diaphragm formation during embryogenesis. The diaphragmatic defect allows for herniation of abdominal viscera into the chest, and the resulting pulmonary hypoplasia and pulmonary hypertension can lead to cardiorespiratory failure in the neonatal period. There is a wide spectrum of disease severity in CDH, and while advances in neonatal care and the introduction of extracorporeal membrane oxygenation have improved outcomes in many cases, the most severe defects are still associated with high morbidity and mortality. Improvements in prenatal diagnostic and prognostic capabilities have created an opportunity to select high risk patients for fetal intervention. Three decades of refinements in the fetal surgical therapy for CDH have led to the current technique of Fetoscopic Endoluminal Tracheal Occlusion (FETO). Herein, we review the current considerations for selecting patients for fetal intervention, and the contemporary fetal surgical operation for CDH, FETO, with a focus on early outcomes and ongoing studies.

Interhospital Transport on Extracorporeal Membrane Oxygenation of Neonates-Perspective for the Future

In recent years the number of extracorporeal membrane oxygenation (ECMO) cases in neonates has been relatively constant. Future expansion lays in new indications for treatment. Regionalization to high-volume ECMO centers allows for optimal utilization of resources, reduction in costs, morbidity, and mortality. Mobile ECMO services available "24-7" are needed to provide effective logistics and reliable infrastructure for patient safety. ECMO transports are usually high-risk and complex. To reduce complications during ECMO transport communication using time-out, checklists, and ECMO A-B-C are paramount in any size mobile program. Team members' education, clinical training, and experience are important. For continuing education, regular wet-lab training, and simulation practices in teams increase performance and confidence. In the future the artificial placenta for the extremely premature infant (23-28 gestational weeks) will be introduced. This will enforce the development and adaptation of ECMO devices and materials for increased biocompatibility to manage the high-risk prem-ECMO (28-34 weeks) patients. These methods will likely first be introduced at a few high-volume neonatal ECMO centers. The ECMO team brings bedside competence for assessment, cannulation, and commencement of therapy, followed by a safe transport to an experienced ECMO center. How transport algorithms for the artificial placentae will affect mobile ECMO is unclear. ECMO transport services in the newborn should firstly be an out-reach service led and provided by ELSO member centers that continuously report transport data to an expansion of the ELSO Registry to include transport quality follow-up and research. For future development and improvement follow-up and sharing of data are important.

The experience of breastfeeding infants affected by congenital diaphragmatic hernia or esophageal atresia

Background

Newborns with congenital diaphragmatic hernia (CDH) and esophageal atresia (EA) might experience breastfeeding difficulties. The aim of this study was to detect the prevalence of breastfeeding in newborns with CDH and EA at different time points.

Methods

We performed an epidemiological study and retrospective survey on the prevalence of breastfeeding in CDH and EA affected newborns. We identified 40 CDH and 25 EA newborns who were fed through breastfeeding procedures according to WHO categorized definitions, and compared the breastfeeding procedures at the beginning of hospitalization and at three months of life.

Results

Although all the mothers attempted breastfeeding after birth, only 44 (67.7%) were still breastfeeding at the time of discharge. Exclusive breastfeeding was successful for only 19 (29%) mothers. The rate of exclusive breastfeeding at three months of life did not differ statistically from discharge and between the two groups of study.

Conclusion

A large percentage of mothers of children with CDH and EA who breastfed at the beginning of hospitalization did not continue at three months. It would be important to increase the breastfeeding rate in CDH and EA affected newborns by following specific steps for vulnerable infants and sustaining breastfeeding after discharge.

Minimally Invasive Fetal Surgery

Fetal surgery corrects severe congenital anomalies in utero to prevent their severe consequences on fetal development. The significant risk of open fetal operations to the pregnant mother has driven innovation toward minimally invasive procedures that decrease the risks inherent to hysterotomy. In this article, we discuss the basic principles of minimally invasive fetal surgery, the general history of its development, specific conditions and procedures used to treat them, and the future of the field.

Comorbid Conditions in Neonates With Congenital Heart Disease

OBJECTIVES

The objectives of this review are to discuss the pathophysiology, clinical impact and treatment of major noncardiac anomalies, and prematurity in infants with congenital heart disease.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSION

Mortality risk is significantly higher in patients with congenital heart disease and associated anomalies compared with those in whom the heart defect occurs in isolation. Although most noncardiac structural anomalies do not require surgery in the neonatal period, several require surgery for survival. Management of such infants poses multiple challenges. Premature infants with congenital heart disease face challenges imposed by their immature organ systems, which are susceptible to injury or altered function by congenital heart disease and abnormal circulatory physiology independent of congenital heart disease. For optimal outcomes in premature infants or in infants with multiple congenital anomalies, a collaborative interdisciplinary approach is necessary.

Prenatally diagnosed severe CDH: mortality and morbidity remain high

PURPOSE

This study sought to evaluate prenatal markers' ability to predict severe congenital diaphragmatic hernia(CDH) and assess this subgroup's morbidity and mortality.

METHODS

A retrospective review was performed between 2006 and 2014. Prenatal criteria for severe CDH included: liver herniation, lung-to-head ratio (LHR) <1 on prenatal ultrasound and/or observed-to-expected LHR (o/eLHR) <25%, and/or observed-to-expected total lung volume (o/eTLV) <25% on fetal MRI. Postnatal characteristics included: mortality, ECMO utilization, patch closure, persistent suprasystemic pulmonary hypertension (PHtn), O2 requirement at discharge, and few ventilator-free days in the first 60. Statistics performed used unpaired t-test, p<0.05 significant.

RESULTS

Overall, 47.5%(29/61) of patients with prenatally diagnosed, isolated CDH met severe criteria. Mean LHR: 1.04±0.35, o/eLHR: 31±10% and o/eTLV: 20±7%. Distribution was 72% LCDH, 24% R-CDH. Overall survival: 38%. ECMO requirement: 92%. Patch rate: 91%. Mean ventilator-free days in 60: 7.1±14. Supplemental oxygen at discharge was required in 27%. In this prenatally diagnosed severe cohort, 58%(15/26) had persistent PHtn post-ECMO requiring inhaled nitric oxide±epoprostenol. Comparing patients with and without PHtn: mean ECMO duration 18±10 days versus 9±7 days (p=0.01) and survival 20% versus 72% (p=0.006).

CONCLUSION

A combination of prenatal markers accurately identified severe CDH patients. Outcomes of this group remain poor and persistent PHtn contributes significantly to mortality.