Antenatal management of isolated congenital diaphragmatic hernia today and tomorrow: ongoing collaborative research and development. Journal of Pediatric Surgery Lecture

Beyond Bronchopulmonary Dysplasia: A Comprehensive Review of Chronic Lung Diseases in Neonates

In neonates, pulmonary diseases such as bronchopulmonary dysplasia and other chronic lung diseases (CLDs) pose significant challenges due to their complexity and high degree of morbidity and mortality. This review discusses the etiology, pathophysiology, clinical presentation, and diagnostic criteria for these conditions, as well as current management strategies. The review also highlights recent advancements in understanding the pathophysiology of these diseases and evolving strategies for their management, including gene therapy and stem cell treatments. We emphasize how supportive care is useful in managing these diseases and underscore the importance of a multidisciplinary approach. Notably, we discuss the emerging role of personalized medicine, enabled by advances in genomics and precision therapeutics, in tailoring therapy according to an individual's genetic, biochemical, and lifestyle factors. We conclude with a discussion on future directions in research and treatment, emphasizing the importance of furthering our understanding of these conditions, improving diagnostic criteria, and exploring targeted treatment modalities. The review underscores the need for multicentric and longitudinal studies to improve preventative strategies and better understand long-term outcomes. Ultimately, a comprehensive, innovative, and patient-centered approach can enhance the quality of care and outcomes for neonates with CLDs.

Epidemiologic and clinical characteristics of selected congenital anomalies at the largest Bosnian pediatric surgery tertiary center

Congenital anomalies (CA) are any abnormality present at birth, either structural or functional, that may potentially affect an infant's health, development, and/or survival. There is a paucity of studies on clinical characteristics and outcomes of CA in Bosnia and Herzegovina, mainly due to the lack of a nationwide congenital malformations monitoring system. A 5-year hospital-based study was conducted to determine the prevalence at birth and clinical characteristics of selected major CA in Sarajevo Canton, Bosnia and Herzegovina. Ninety-one CA were observed from 2012 to 2016 (the overall prevalence was 39.6 cases/10,000 live births). The mean age of neonates at diagnosis was 3 days. The gastrointestinal tract was the most commonly affected system (76.9%), with esophageal atresia (EA) being the most frequent (17.6% of all CA). Major CA were more prevalent among preterm infants than term infants (P = .001), particularly in males (61.5% vs. 38.5%; P = .028; M:F ratio was 1.59). Multiple CA were seen in 37.4% of neonates. The overall mortality rate of neonates was 11%, and the median length of hospital stay was 19.8 days. Our study revealed the distribution and clinical patterns of common major CA in the largest tertiary care facility in Bosnia and Herzegovina. It also confirmed a relatively high mortality rate, which requires further efforts to improve the quality of neonatal care in the country.

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.

Fetal body MRI for fetal and perinatal management

Fetal magnetic resonance imaging (MRI) has become a valuable adjunct to ultrasound (US) in diagnosing fetal abnormalities. This review is intended to highlight the contribution of MRI in parental counselling and perinatal treatment. A state-of-the-art fetal MRI protocol with experts of maternal-fetal medicine present in the MRI suite allows emphasis on patient-centred care and maximises therapeutic options.

Evaluation of a new balloon for fetal endoscopic tracheal occlusion in the nonhuman primate model

OBJECTIVE

We developed a new balloon called "Smart-TO," which allows noninvasive and easy unplugging, thanks to a magnetic valve actuated by the magnetic fringe field of a magnetic resonance imaging (MRI) scanner. The objective of this feasibility study was to evaluate the operation of this new balloon in a nonhuman primate model.

METHODS

Four pregnant rhesus monkeys underwent fetal endoscopic tracheal occlusion using the "Smart-TO" balloon. The pregnant monkeys were simply carried around the perimeter of an MRI scanner a few days later. Study outcomes were feasibility of fetal tracheal occlusion using the "Smart-TO" balloon, persistence of the balloon in the fetal trachea, and deflation of the balloon when subjected to the magnetic fringe field of an MRI.

RESULTS

At the time of the unplug procedure, in all cases, the balloon was still in a correct position, and its shape did not change based on their ultrasound appearance. After bringing the pregnant monkeys into the fringe field of the MRI scanner, the balloon deflated in all cases.

CONCLUSION

The balloon we developed allows noninvasive, easily triggered, and externally controlled reversal occlusion, based on the nonhuman primate model. Further tests evaluating occlusiveness and potential adverse effects are necessary.

The impact of fetal endoscopic tracheal occlusion in isolated left-sided congenital diaphragmatic hernia on left-sided cardiac dimensions

OBJECTIVES

Fetal endoscopic tracheal occlusion (FETO) is offered to fetuses with congenital diaphragmatic hernia (CDH) and severe lung hypoplasia to promote lung growth and may secondarily affect left heart growth. The effects of FETO on left heart hypoplasia (LHH) are not described post-CDH repair.

METHODS

A retrospective analysis was performed for fetuses with left-sided CDH who underwent FETO and severity-matched controls from 2007 to 2016 at our institution. Echocardiographic, ultrasound, and MRI data were reviewed. Left heart dimensions were assessed prenatally and postnatally. Primary clinical outcome evaluated was death.

RESULTS

Twelve FETO patients and 18 controls were identified. Fetal LHH was noted in both groups and worsened after FETO. Postnatal mitral valve dimensions were larger in the FETO group pre-CDH repair (P = .03). Post-CDH repair, mitral valve and left ventricular dimensions were not significantly different between groups (P = .79 and P = .63 respectively) while FETO aortic valve dimensions were smaller (P = .04). Extracorporeal membrane oxygenation use was lower in the FETO group. No associations were found between left heart dimensions and outcomes.

CONCLUSION

Although increased lung growth was seen after FETO, fetal LHH persisted with relative normalization seen post-repair. Persistent LHH post-FETO could be secondary to a small contribution of pulmonary venous return to the fetal left heart and increased intrathoracic pressures post-FETO.

Fetal subcutaneous cells have potential for autologous tissue engineering

Major congenital malformations affect up to 3% of newborns. Infants with prenatally diagnosed soft tissue defects should benefit from having autologous tissue readily available for surgical implantation in the perinatal period. In this study, we investigate fetal subcutaneous cells as cellular source for tissue engineering. Fetal subcutaneous biopsies were collected from elective terminations at gestational Week 20-21. Cells were isolated, expanded, and characterized in vitro. To determine cell coverage, localization, viability, and proliferation in different constructs, the cells were seeded onto a matrix (small intestine submucosa) or in collagen gel with or without poly(ε-caprolactone) mesh and were kept in culture for up to 8 weeks before analysis. Angiogenesis was analysed through a tube-forming assay. Fetal subcutaneous cells could be expanded until 43 ± 3 population doublings, expressed mesenchymal markers, and readily differentiate into adipogenic and osteogenic lineages. The cells showed low adherence to small intestine submucosa and did not migrate deep into the matrix. However, in collagen gels, the cells migrated into the gel and proliferated with sustained viability for up to 8 weeks. The cells in the matrices expressed Ki67, CD73, and α-smooth muscle actin but not cytokeratin or CD31. Fetal cells derived from subcutaneous tissue demonstrated favourable characteristics for preparation of autologous tissue transplants before birth. Our study supports the theory that cells could be obtained from the fetus during pregnancy for tissue engineering purposes after birth. In a future clinical situation, autologous transplants could be used for reconstructive surgery in severe congenital malformations.

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.

Regenerative medicine solutions in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) remains a major challenge and associated mortality is still significant. Patients have benefited from current therapeutic options, but most severe cases are still associated to poor outcome. Regenerative medicine is emerging as a valid option in many diseases and clinical trials are currently happening for various conditions in children and adults. We report here the advancement in the field which will help both in the understanding of further CDH development and in offering new treatment options for the difficult situations such as repair of large diaphragmatic defects and lung hypoplasia. The authors believe that advancements in regenerative medicine may lead to increase of CDH patients׳ survival.

Fetal left-sided cardiac structural dimensions in left-sided congenital diaphragmatic hernia - association with severity and impact on postnatal outcomes

OBJECTIVES

Fetuses with congenital diaphragmatic hernia (CDH) demonstrate varying degrees of left heart hypoplasia. Our study assesses the relationship between fetal left-sided cardiac structural dimensions, lung size, percentage liver herniation, lung-to-head ratio, postnatal left-sided cardiac structural dimensions, and postnatal outcomes.

METHODS

We performed a retrospective cohort study of fetuses with left-sided CDH who had prenatal echocardiographic, ultrasound, and magnetic resonance imaging examinations at our institution between January 2007 and March 2015. Postnatal outcomes assessed include use of inhaled nitric oxide (iNO), use of extracorporeal membrane oxygenation, and death.

RESULTS

Fifty-two fetuses with isolated left-sided CDH were included. Multivariate logistic regression models indicated that smaller fetal aortic valve z-score was associated with postnatal use of iNO (p = 0.03). Fetal mitral valve z-score correlated with lung-to-head ratio (p = 0.04), postnatal mitral valve z-score correlated with percent liver herniation (p = 0.03), and postnatal left ventricular end-diastolic dimension z-score correlated with liver herniation <20% (p = 0.04).

CONCLUSION

We identified associations between smaller fetal left-sided cardiac structural dimensions and classic CDH indices. Smaller aortic valve z-score was associated with iNO use; however, left heart dimensions showed no association with extracorporeal membrane oxygenation or mortality. Further study into the impact of left-sided hypoplasia on outcomes in CDH is worthy of evaluation in a larger, prospective study. © 2017 John Wiley & Sons, Ltd.

The Surgical Correction of Congenital Deformities: The Treatment of Diaphragmatic Hernia, Esophageal Atresia and Small Bowel Atresia

BACKGROUND

More than half of all congenital deformities can be detected in utero. The initial surgical correction is of paramount importance for the achievement of good long-term results with low surgical morbidity and mortality.

METHODS

Selective literature review and expert opinion.

RESULTS

Congenital deformities are rare, and no controlled trials have been performed to determine their optimal treatment. In this article, we present the prenatal assessment, treatment, and long-term results of selected types of congenital deformity. Congenital diaphragmatic hernia (CDH) affects one in 3500 live-born infants, while esophageal atresia affects one in 3000 and small-bowel atresia one in 5000 to 10,000. If a congenital deformity is detected and its prognosis can be reliably inferred from a prenatal assessment, the child should be delivered at a specialized center (level 1 perinatal center). The associated survival rates are 60-80% after treatment for CDH and well over 90% after treatment for esophageal or small-bowel atresia. Despite improvements in surgical correction over the years, complications and comorbidities still affect 20-40% of the treated children. These are not limited to surgical complications in the narrow sense, such as recurrence, postoperative adhesions and obstruction, stenoses, strictures, and recurrent fistulae, but also include pulmonary problems (chronic lung disease, obstructive and restrictive pulmonary dysfunction), gastrointestinal problems (dysphagia, gastro-esophageal reflux, impaired intestinal motility), and failure to thrive. Moreover, the affected children can develop emotional and behavioral disturbances. Minimally invasive surgery in experienced hands yields results as good as those of conventional surgery, as long as proper selection criteria are observed.

CONCLUSION

Congenital deformities should be treated in recognized centers with highly experienced interdisciplinary teams. As no randomized trials of surgery for congenital deformities are available, longitudinal studies and registries will be very important in the future.

Venovenous ECMO for Congenital Diaphragmatic Hernia: Role of Ductal Patency and Lung Recruitment

We report a case of antenatally diagnosed left-sided congenital diaphragmatic hernia, managed on venovenous extracorporeal membrane oxygenation with an hemodynamic and ventilation strategy aimed at preventing left and right ventricular dysfunction. Keeping the ductus arteriosus open with prostaglandin infusion and optimizing lung recruitment were effective in achieving hemodynamic stabilization and an ideal systemic oxygen delivery. The patient was discharged from the hospital and had normal development at 1 year of age. The combination of ductal patency and lung recruitment has not been previously reported as a strategy to stabilize congenital diaphragmatic hernia patients undergoing venovenous extracorporeal membrane oxygenation. We believe that this approach may deserve further evaluation in prospective studies.

Clinically relevant timing of antenatal sildenafil treatment reduces pulmonary vascular remodeling in congenital diaphragmatic hernia

Patients with congenital diaphragmatic hernia (CDH) suffer from severe pulmonary hypertension attributable to altered development of the pulmonary vasculature, which is often resistant to vasodilator therapy. Present treatment starts postnatally even though significant differences in the pulmonary vasculature are already present early during pregnancy. We examined the effects of prenatal treatment with the phosphodiesterase-5 inhibitor sildenafil on pulmonary vascular development in experimental CDH starting at a clinically relevant time. The well-established, nitrofen-induced CDH rodent model was treated daily with 100 mg/kg sildenafil from day 17.5 until day 20.5 of gestation (E17.5–20.5). Importantly, this timing perfectly corresponds to the developmental stage of the lung at 20 wk of human gestation, when CDH is detectable by 2D-ultrasonography and/or MRI. At E21.5 pups were delivered by caesarean section and euthanized by lethal injection of pentobarbital. The lungs were isolated and subsequently analyzed using immunostaining, real-time PCR, and volume measurements. Prenatal treatment with sildenafil improved lung morphology and attenuated vascular remodeling with reduced muscularization of the smaller vessels. Pulmonary vascular volume was not affected by sildenafil treatment. We show that prenatal treatment with sildenafil within a clinically relevant period improves pulmonary vascular development in an experimental CDH model. This may have important implications for the management of this disease and related pulmonary vascular diseases in human.

Fetal magnetic resonance imaging and ultrasound

Magnetic resonance imaging (MRI) has been increasingly adopted in obstetrics practice in the past three decades. MRI aids prenatal ultrasound and improves diagnostic accuracy for selected maternal and fetal conditions. However, it should be considered only when high-quality ultrasound cannot provide certain information that affects the counseling, prenatal intervention, pregnancy course, and delivery plan. Major indications of fetal MRI include, but are not restricted to, morbidly adherent placenta, selected cases of fetal brain anomalies, thoracic lesions (especially in severe congenital diaphragmatic hernia), and soft tissue tumors at head and neck regions of the fetus. For fetal anatomy assessment, a 1.5-Tesla machine with a fast T2-weighted single-shot technique is recommended for image requisition of common fetal abnormalities. Individual judgment needs to be applied when considering usage of a 3-Tesla machine. Gadolinium MRI contrast is not recommended during pregnancy. MRI should be avoided in the first half of pregnancy due to small fetal structures and motion artifacts. Assessment of fetal cerebral cortex can be achieved with MRI in the third trimester. MRI is a viable research tool for noninvasive interrogation of the fetus and the placenta.

Management of pulmonary hypertension in infants with congenital diaphragmatic hernia

In infants with congenital diaphragmatic hernia (CDH), a posterolateral diaphragmatic defect results in herniation of abdominal contents into the chest and compression of the intrathoracic structures. In the most severe cases, hypoplasia of the ipsilateral and contralateral lungs, severe pulmonary hypertension (PH) and left ventricular (LV) hypoplasia/dysfunction all contribute to increased mortality. The management of PH in CDH is complicated by structural and functional changes in the heart, pulmonary vasculature, airways and lung parenchyma; consequently, determining optimal management strategies is challenging. Treatment of PH in patients with CDH changes as the underlying pathophysiology evolves in the days and weeks after birth. During the early transition, the use of pulmonary vasodilators is limited by LV structural and functional abnormalities, and pulmonary vasodilators such as inhaled nitric oxide (iNO) may have a limited role (for example, stabilization for extracorporeal membrane oxygenation (ECMO), treatment of marked preductal desaturation and treatment of PH as LV performance improves). In contrast, subacute treatment of PH in CDH with iNO has an important role in recurrent or persistent PH and potentially improves survival. Chronic PH and vascular abnormalities may persist into childhood in patients with CDH, contributing to late mortality. It is unclear how pulmonary vasodilator therapies, such as iNO, sildenafil and bosentan, will modulate late outcomes in CDH with late/chronic PH.

In vivo evidence by magnetic resonance volumetry of a gestational age dependent response to tracheal occlusion for congenital diaphragmatic hernia

OBJECTIVE

We aimed to assess in vivo changes in lung and liver volumes in fetuses with isolated congenital diaphragmatic hernia, either expectantly managed or treated in utero.

METHOD

This is a secondary analysis of prospectively collected data at two fetal therapy centers. We used archived magnetic resonance images of fetuses taken ≥7 days apart, creating paired observations in 20 expectantly managed cases, 41 with a second magnetic resonance prior to balloon reversal and 64 after balloon removal. We measured observed to expected total fetal lung volume (O/E TFLV) and liver-to-thoracic volume ratio. We calculated changes in volume as compared with the initial measurement and its rate as a function of gestational age (GA) at occlusion.

RESULTS

The liver-to-thoracic volume ratio did not change in either group. In expectantly managed fetuses, O/E TFLV did not increase with gestation. In fetuses undergoing tracheal occlusion, the measured increase in volume was 2.6 times larger with balloon in place as compared with that after its removal. GA at tracheal occlusion was an independent predictor of the O/E TFLV. The net rate seems to initially increase and plateau at a maximum of 1.5% per week by 35 to 45 days after occlusion.

CONCLUSIONS

Tracheal occlusion induces a net increase in volume, its magnitude essentially dependent on the GA at occlusion.

Controversies in the management of severe congenital diaphragmatic hernia

Despite years of progress in perinatal care, severe congenital diaphragmatic hernia (CDH) remains a clinical challenge. Controversies include almost every facet of clinical care: the definition of severe CDH by prenatal and postnatal criteria, fetal surgical intervention, ventilator management, pulmonary hypertension management, use of extracorporeal membrane oxygenation, surgical considerations, and long-term follow-up. Breakthroughs are likely only possible by sharing of experience, collaboration between institutions and innovative therapies within well-designed multicenter clinical trials.

Understanding and treating pulmonary hypertension in congenital diaphragmatic hernia

Lung hypoplasia and pulmonary hypertension are classical features of congenital diaphragmatic hernia (CDH) and represent the main determinants of survival. The mechanisms leading to pulmonary hypertension in this malformation are still poorly understood, but may combine altered vasoreactivity, pulmonary artery remodeling, and a hypoplastic pulmonary vascular bed. Efforts have been directed at correcting the "reversible" component of pulmonary hypertension of CDH. However, pulmonary hypertension in CDH is often refractory to pulmonary vasodilators. A new emerging pattern of late (months after birth) and chronic (months to years after birth) pulmonary hypertension are described in CDH survivors. The true incidence and implications for outcome and management need to be confirmed by follow-up studies from referral centers with high patient output. In order to develop more efficient strategies to treat pulmonary hypertension and improve survival in most severe cases, the ultimate therapeutic goal would be to promote lung and vascular growth.

Comparison of matching by body volume or gestational age for calculation of observed to expected total lung volume in fetuses with isolated congenital diaphragmatic hernia

OBJECTIVE

To determine the bias induced by matching fetuses according to gestational age (GA) or fetal body volume (FBV) when calculating the observed to expected total fetal lung volume (o/e TFLV) in cases of isolated congenital diaphragmatic hernia (CDH).

METHODS

This was a single-center, retrospective study on archived magnetic resonance (MR) images of fetuses with isolated CDH over a 10-year period. We retrieved the TFLV, GA and o/e TFLVGA , and delineated FBV to obtain TFLVFBV in each case. We evaluated the relationship between o/e TFLVFBV and o/e TFLVGA by Bland-Altman analysis. All outliers were manually identified, and their specific clinical features were retrieved.

RESULTS

Records of a total of 377 MR examinations of 225 fetuses were identified and included in the analysis. The mean ( ± SD) time spent on FBV measurement was 16.12 ± 4.95 min. On reproducibility analysis of FBV measurement (n = 10), the intraobserver intraclass correlation coefficient (ICC) was 0.998 and the interobserver ICC was 0.999. FBV was highly correlated with GA (R(2)  = 0.899; P < 0.0001). There was good agreement between o/e TFLVGA and o/e TFLVFBV , with a mean difference of -1.10% and 95% limits of agreement of -8.58 to 6.39. There were no outliers in fetuses that had an o/e TFLV < 25%. Discrepancies induced by different methods were more likely in women with a body mass index ≥ 25 kg/m(2) (+16.5%), fetuses with an estimated fetal weight (EFW) ≤ 10(th) centile (+21.3%) or an EFW > 90(th) centile (+14.7%).

CONCLUSIONS

Discrepancies in matching by FBV and GA when calculating o/e TFLV are more likely in fetuses with an abnormal EFW or in fetuses carried by overweight women. The clinical relevance of using FBV rather than GA for calculation of the o/e TFLV might be limited, as there was no discrepancy between the two methods in fetuses with small lungs ( < 25%), which is the group of most interest for lung volume assessment.

Intrapulmonary instillation of perflurooctylbromide improves lung growth, alveolarization, and lung mechanics in a fetal rabbit model of diaphragmatic hernia

OBJECTIVES

Fetal tracheal occlusion of hypoplastic rabbit lungs results in lung growth and alveolarization although the surfactant protein messenger RNA expression is decreased and the transforming growth factor-β pathway induced. The prenatal filling of healthy rabbit lungs with perfluorooctylbromide augments lung growth without suppression of surfactant protein synthesis. We hypothesizes that Intratracheal perfluorooctylbromide instillation improves lung growth, mechanics, and extracellular matrix synthesis in a fetal rabbit model of lung hypoplasia induced by diaphragmatic hernia.

SETTING AND INTERVENTIONS

On day 23 of gestation, DH was induced by fetal surgery in healthy rabbit fetuses. Five days later, 0.8ml of perfluorooctylbromide (diaphragmatic hernia-perfluorooctylbromide) or saline (diaphragmatic hernia-saline) was randomly administered into the lungs of previously operated fetuses. After term delivery (day 31), lung mechanics, lung to body weight ratio, messenger RNA levels of target genes, assessment of lung histology, and morphological distribution of elastin and collagen were determined. Nonoperated fetuses served as controls.

MEASUREMENTS AND MAIN RESULTS

Fetal instillation of perfluorooctylbromide in hypoplastic lungs resulted in an improvement of lung-to-body weight ratio (0.016 vs 0.013 g/g; p = 0.05), total lung capacity (23.4 vs 15.4 μL/g; p = 0.03), and compliance (2.4 vs 1.2 mL/cm H2O; p = 0.007) as compared to diaphragmatic hernia-saline. In accordance with the results from lung function analysis, elastin staining of pulmonary tissue revealed a physiological distribution of elastic fiber to the tips of the secondary crests in the diaphragmatic hernia-perfluorooctylbromide group. Likewise, messenger RNA expression was induced in genes associated with extracellular matrix remodeling (matrix metalloproteinase-2, tissue inhibitor of metalloproteinase-1, and tissue inhibitor of metalloproteinase-2). Surfactant protein expression was similar in the diaphragmatic hernia-perfluorooctylbromide and diaphragmatic hernia-saline groups. Distal airway size, mean linear intercept, as well as airspace and tissue fractions were similar in diaphragmatic hernia-perfluorooctylbromide, diaphragmatic hernia-saline, and control groups.

CONCLUSIONS

Fetal perfluorooctylbromide treatment improves lung growth, lung mechanics, and extracellular matrix remodeling in hypoplastic lungs, most probably due to transient pulmonary stretch, preserved fetal breathing movements, and its physical characteristics. Perfluorooctylbromide instillation is a promising approach for prenatal therapy of lung hypoplasia.

Congenital diaphragmatic hernia: where and what is the evidence?

Congenital diaphragmatic hernia (CDH) retains high mortality and morbidity due to lung hypoplasia, pulmonary hypertension and severe co-existent anomalies. This article offers a comprehensive state-of-the-art review for the paediatric surgeon whilst also describing key contributions from the basic sciences in the search to uncover the cause of the birth defect together with efforts to develop new and better therapies for CDH.

Therapeutic potential of mesenchymal stem cell transplantation in a nitrofen-induced congenital diaphragmatic hernia rat model

PURPOSE

The aim of this study was to evaluate the efficacy of mesenchymal stem cells (MSCs) in a nitrofen-induced congenital diaphragmatic hernia (CDH) rat model.

METHODS

Pregnant rats were exposed to nitrofen on embryonic day 9.5 (E9.5). MSCs were isolated from the enhanced green fluorescent protein (eGFP) transgenic rat lungs. The MSCs were transplanted into the nitrofen-induced E12.5 rats via the uterine vein, and the E21 lung explants were harvested. The study animals were divided into three: the control group, the nitrofen-induced left CDH (CDH group), and the MSC-treated nitrofen-induced left CDH (MSC-treated CDH group). The specimens were morphologically analyzed using HE and immunohistochemical staining with proliferating cell nuclear antigen (PCNA), surfactant protein-C (SP-C), and α-smooth muscle actin.

RESULTS

The alveolar and medial walls of the pulmonary arteries were significantly thinner in the MSC-treated CDH group than in the CDH group. The alveolar air space areas were larger, while PCNA and the SP-C positive cells were significantly higher in the MSC-treated CDH group, than in the CDH group. MSC engraftment was identified on immunohistochemical staining of the GFP in the MSC-treated CDH group.

CONCLUSIONS

MSC transplantation potentially promotes alveolar and pulmonary artery development, thereby reducing the severity of pulmonary hypoplasia.

The lung to thorax transverse area ratio has a linear correlation with the observed to expected lung area to head circumference ratio in fetuses with congenital diaphragmatic hernias

BACKGROUND/PURPOSE

The purpose of this study was to clarify the relationship between the lung to thorax transverse area ratio (L/T ratio) and the observed to expected lung area to head circumference ratio (O/E LHR), based on the results of a nationwide Japanese survey conducted in 2011, and to evaluate the compatibility of these prognostic predictors of fetal CDH.

METHODS

Two hundred and forty-two prenatally diagnosed isolated CDH patients born between 2006 and 2010 were included in the present analysis. A regression analysis was conducted to investigate the relationship between the L/T ratio and the O/E LHR based on 191 simultaneous measurements of these parameters in 120 patients.

RESULTS

The linear regression equation between the L/T ratio and the O/E LHR was: L/T ratio=0.0233+(0.00222×O/E LHR), (R=0.847, p<0.0001). According to this equation, 25% of the O/E LHR, the cut-off value used in the fetal intervention for CDH, was equivalent to an L/T ratio of 0.08, a commonly accepted cut-off value for identifying the most severe cases of fetal CDH.

CONCLUSIONS

As there is a positive correlation between the L/T ratio and the O/E LHR, these two parameters proved to be used interchangeably according to the linear regression equation.

Comparison of ultrasound and magnetic resonance imaging parameters in predicting survival in isolated left-sided congenital diaphragmatic hernia

OBJECTIVE

To compare test characteristics of ultrasound- and magnetic resonance imaging (MRI)-derived parameters in predicting newborn survival in cases of isolated left-sided congenital diaphragmatic hernia (CDH).

METHODS

This was a retrospective study involving 85 fetuses with an isolated left CDH. All had detailed prenatal evaluation, prenatal care, delivery and postnatal care at a single institution. Ultrasound images were reviewed to allow calculation of the lung-to-head ratio (LHR) and the observed/expected LHR (O/E-LHR), and MRI images were reviewed to determine the observed/expected total lung volume (O/E-TLV) and the percent herniated liver (%HL). Univariable logistic regression was used to evaluate each parameter for its ability to predict survival. Receiver-operating characteristics (ROC) curves were constructed and test characteristics were determined for each parameter as a predictor of survival.

RESULTS

The overall survival for all fetuses included was 65%. Pseudo-R(2) values for all parameters were similar and were statistically significant as predictors of survival, with %HL having the highest pseudo-R(2) , of 0.28. ROC curve analysis showed ultrasound-determined parameters (LHR and O/E-LHR) to have a similar area under the curve (AUC), of 0.70, whilst MRI parameters (O/E-TLV and %HL) had AUC values of 0.82 and 0.84, respectively. At ROC-curve-determined cut-off values, MRI parameters had better test characteristics than did ultrasound parameters. At a standardized 5% false-positive rate, %HL performed best, with a sensitivity of 0.54 and a specificity of 0.95. At clinically employed cut-off values, sensitivity was similar for all parameters but MRI parameters provided the best combination of sensitivity and specificity, as evidenced by better likelihood ratios.

CONCLUSIONS

A variety of measures have been proposed as antenatal predictors of survival in CDH. Ultrasound parameters function at a similar level, whereas MRI-determined parameters appear to offer better predictive value.

Comparative analysis of multilineage properties of mesenchymal stromal cells derived from fetal sources shows an advantage of mesenchymal stromal cells isolated from cord blood in chondrogenic differentiation potential

Background aims

Cord blood (CB) and amniotic fluid (AF) could represent new and attractive mesenchymal stromal cell (MSC) sources, but their potential therapeutic applications are still limited by lack of standardized protocols for isolation and differentiation. In particular, chondrogenic differentiation has never been deeply investigated.

Methods

MSCs were obtained from CB and AF samples collected during cesarean sections at term and compared for their biological and differentiation properties, with particular interest in cartilage differentiation, in which quantitative real-time polymerase chain reaction and immunohistochemical analyses were performed to evaluate the expression of type 2 collagen, type 10 collagen, SRY-box9 and aggrecan.

Results

We were able to isolate MSCs from 12 of 30 (40%) and 5 of 20 (25%) CB and AF units, respectively. Fluorescence in situ hybridization analysis indicated the fetal origin of isolated MSC strains. Both populations expressed mesenchymal but not endothelial and hematopoietic markers, even though we observed a lower expression of human leukocyte antigen (HLA) I in CB-MSCs. No differences in proliferation rate and cell cycle analysis could be detected. After osteogenic induction, both populations showed matrix mineralization and typical marker expression. Under chondrogenic conditions, pellets derived from CB-MSCs, in contrast with AF-MSCs pellets, were significantly larger, showed cartilage-like morphology and resulted positive for chondrocyte-associated markers, such as type 2 collagen, type 10 collagen, SRY-box9 and aggrecan.

Conclusions

Our results show that CB-MSCs and AF-MSCs collected at term differ from each other in their biological and differentiation properties. In particular, only CB-MSCs showed a clear chondrogenic potential and thus could represent an ideal candidate for cartilage-tissue engineering.

Identification of dosage-sensitive genes in fetuses referred with severe isolated congenital diaphragmatic hernia

OBJECTIVE

Congenital diaphragmatic hernia (CDH) is a fetal abnormality affecting diaphragm and lung development with a high mortality rate despite advances in fetal and neonatal therapy. CDH may occur either as an isolated defect or in syndromic form for which the prognosis is worse. Although conventional karyotyping and, more recently, chromosomal microarrays support a substantial role for genetic factors, causal genes responsible for isolated CDH remain elusive. We propose that chromosomal microarray analysis will identify copy number variations (CNVs) associated with isolated CDH.

METHODS

We perform a prospective genome-wide screen for CNVs using chromosomal microarrays on 75 fetuses referred with apparently isolated CDH, six of which were later reclassified as non-isolated CDH.

RESULTS

The results pinpoint haploinsufficiency of NR2F2 as a cause of CDH and cardiovascular malformations. In addition, the 15q25.2 and 16p11.2 recurrent microdeletions are associated with isolated CDH. By using gene prioritisation and network analysis, we provide strong evidence for several novel dosage-sensitive candidate genes associated with CDH.

CONCLUSIONS

Chromosomal microarray analysis detects submicroscopic CNVs associated with isolated CDH or CDH with cardiovascular malformations.

Management of prenatally diagnosed congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a congenital anomaly that presents with a broad spectrum of severity that is dependent upon components of pulmonary hypoplasia and pulmonary hypertension. While advances in neonatal care have improved the overall survival of CDH in experienced centers, mortality and morbidity remain high in a subset of CDH infants with severe CDH. Prenatal predictors have been refined for the past two decades and are the subject of another review in this issue. So far, all randomized trials comparing prenatal intervention to standard postnatal therapy have shown no benefit to prenatal intervention. Although recent non-randomized reports of success with fetoscopic endoluminal tracheal occlusion (FETO) and release are promising, prenatal therapy should not be widely adopted until a well-designed prospective randomized trial demonstrating efficacy is performed. The increased survival and subsequent morbidity of CDH survivors has resulted in the need to provide resources for the long-term follow up and support of the CDH population.