Post-natal prognostic factors in CDH: experience of 11 years in a referral center in Brazil

OBJECTIVE

To describe post-natal risk factors associated with death in Newborns (NB) with Congenital Diaphragmatic Hernia (CDH) in a Brazilian reference center.

METHODS

In this retrospective cohort study, post-natal clinical factors of all NB diagnosed with CDH were reviewed in an 11-year period (2007‒2018). The primary outcome was death. Secondary outcomes included clinical features, prognostic indexes, type of mechanical ventilation, complications during hospitalization and surgical repair.

RESULTS

After applying the exclusion criteria, the authors analyzed 137 charts. Overall mortality was 59% (81/137), and the highest rates were observed for low-birth-weight NB (87%), syndromic phenotype (92%), and those with major malformations (100%). Prognostic indexes such as Apgar, SNAPPE-II and 24hOI (best oxygenation index in 24 hours) were all associated with poor evolution. In a multivariate analysis, only birth weight and 24hOI were statistically significant risk factors for mortality, with a reduction in mortality risk of 17.1% (OR = 0.829, 95% IC 0.72‒0.955, p = 0.009) for each additional 100g at birth and an increase by 26.5% (OR = 1.265, 95% IC 1.113‒1.436, p = 0.0003) for each unitary increase at the 24hOI.

CONCLUSION

Prognostic indexes are an important tool for predicting outcomes and improving resource allocation. Post-natal risk factors may be more suitable for settings where antenatal diagnosis is not universal. Classical risk factors, such as prematurity, low birth weight, higher need for supportive care, and poorer prognostic indexes were associated with mortality in our CDH population.

Intra-amniotic sildenafil administration in rabbits: Safety, pharmacokinetics, organ distribution and histologic evaluation

BACKGROUND

The effectiveness of sildenafil in the management of pulmonary hypertension in congenital diaphragmatic hernia (CDH) has been reported but has not been systematically evaluated. Our studies have also demonstrated that intra-amniotic (IA) sildenafil administration improves pulmonary hypertension in CDH.

METHODS

We evaluated the pharmacokinetics of sildenafil after IA administration in pregnant rabbits. Following maternal laparotomy, fetuses received IA injection of 0.8 mg of sildenafil. Maternal blood, amniotic fluid, and fetal tissues were collected at various time points. The concentrations of sildenafil and its major metabolite in samples were analyzed by liquid chromatography-mass spectrometry. To assess organ toxicity, 7 days after IA sildenafil administration, fetal organs were examined histologically.

RESULTS

After IA dosing, sildenafil was absorbed quickly with an absorption half-life of 0.03-0.07 h into the fetal organs. All the organs showed a maximum concentration within 1 h and the disposition half-life ranged from 0.56 to 0.73 h. Most of the sildenafil was eliminated from both mothers and fetuses within 24 h after a single dose. There was no histological evidence of organ toxicity in the fetuses after a single dose of IA administration of sildenafil.

CONCLUSION

IA sildenafil is rapidly absorbed into the fetus, distributes into the mother and is eliminated by the mother without accumulation or fetal organ toxicity. This study confirms the feasibility and the safety of IA administration of sildenafil and enables future applications in the treatment of CDH fetuses.

A Tracheal Aspirate-Derived Airway Basal Cell Model Reveals a Proinflammatory Epithelial Defect in Congenital Diaphragmatic Hernia

RATIONALE

Congenital diaphragmatic hernia (CDH) is characterized by incomplete closure of the diaphragm and lung hypoplasia. The pathophysiology of lung defects in CDH is poorly understood.

OBJECTIVES

To establish a translational model of human airway epithelium in CDH for pathogenic investigation and therapeutic testing.

METHODS

We developed a robust methodology of epithelial progenitor derivation from tracheal aspirates of newborns. Basal stem cells (BSCs) from CDH patients and preterm and term, non-CDH controls were derived and analyzed by bulk RNA-sequencing, ATAC-sequencing, and air-liquid-interface differentiation. Lung sections from fetal human CDH samples and the nitrofen rat model of CDH were subjected to histological assessment of epithelial defects. Therapeutics to restore epithelial differentiation were evaluated in human epithelial cell culture and the nitrofen rat model of CDH.

MEASUREMENTS AND MAIN RESULTS

Transcriptomic and epigenetic profiling of CDH and control BSCs reveals a proinflammatory signature that is manifested by hyperactive NF-κB and independent of severity and hernia size. In addition, CDH BSCs exhibit defective epithelial differentiation in vitro that recapitulates epithelial phenotypes found in fetal human CDH lung samples and fetal tracheas of the nitrofen rat model of CDH. Furthermore, blockade of NF-κB hyperactivity normalizes epithelial differentiation phenotypes of human CDH BSCs in vitro and in nitrofen rat tracheas in vivo.

CONCLUSIONS

Our findings have identified an underlying proinflammatory signature and BSC differentiation defects as a potential therapeutic target for airway epithelial defects in CDH.

The CDH patient perspective journey

Background

Congenital Diaphragmatic Hernia is a malformation of the diaphragm resulting in ongoing clinical symptoms and problems. Mortality remains high, particularly where there are other issues involved. Tracking a patient throughout their lifetime to understand the full impact on health and function is challenging. CDH UK is a registered charity supporting anyone affected by CDH. It has over 25 years of experience and a broad range of patient experience and knowledge.

Aims

To develop a patient journey with timepoints of significance.

Methods

We studied our own data and looked at what we already knew from publications and medical advisors. We recruited a focus group, plotted out stages and timepoints through their "lived" experiences using the Team Idea Mapping method. We then compared these experiences to our own data, to identify the common issues in daily life and care.

Outcome

We have developed a patient journey through the eyes of the patient and turned it into a patient friendly infographic. This can be used as a tool to help understand the CDH Journey throughout a patient's lifetime. CDH UK has already used this to create a first prototype of a mobile application. It has also further helped to recognize areas of patient concern and to improve services and resources.

Discussion

This can be used as a basis for care and research, including standards, benchmarking, transition and helping improvements in healthcare, education, family life and social settings. Potentially holding clues as to the etiology and pathology of the condition and an opportunity to further explore theories and unanswered questions. It may help improve counselling and bereavement care, resulting in better general and mental health outcomes.

Strangulated Left Bochdalek Diaphragmatic Hernia: A Lesson Learned

Congenital Bochdalek diaphragmatic hernia (CDH) is the most common embryologic defect of the diaphragm which occurs 1 in 2500-5000 live births. Most commonly CDH presents soon after birth but it can present late in 10-30% of cases, leading to a diagnostic dilemma. Late presenting patients can remain asymptomatic for a variable period before presenting with complications in the form of obstruction or strangulation of gut. Bochdalek diaphragmatic hernia presenting with strangulation of gut is very rare. We report a case of such a rare variety of strangulated Bochdalek left diaphragmatic hernia in an 11-month-old boy which was managed successfully.

Extracorporeal Membrane Oxygenation (ECMO) Risk Stratification in Newborns with Congenital Diaphragmatic Hernia (CDH)

BACKGROUND

A means for early postnatal stratification of ECMO risk in CDH newborns could be used to comparatively assess the utilization and outcomes of ECMO use between centers. While multiple CDH mortality risk calculators are available, no validated tool exists specifically for prediction of ECMO use. The purpose of this study was to derive and validate an ECMO risk stratification model.

METHODS

The study population was obtained from CDH Study Group registry for the period between 2007 and 2016. Only centers offering ECMO were included. The cohort was restricted to ECMO candidates and then divided into derivation and validation sets. Using all relevant perinatal predictors in the registry, univariate analysis was performed for the composite outcome of ECMO use or death without ECMO use. The model was derived using the derivation cohort with multivariable logistic regression and automatic stepwise forward selection (P < 0.05 for qualifying variables), and a c-statistic was obtained. The model was then tested on the validation cohort. Sample reuse validation and bootstrap validation were performed. The validated model was then tested for accuracy on CDH subgroups.

RESULTS

There were 1992 patients in the derivation cohort. Four significant variables were identified in the final ECMO risk model: 1-min and 5-min Apgar scores and highest and lowest post-ductal partial pressure of CO2 during the first 24 h of life. The model c-statistic was 0.824 which was confirmed with cross-validation and bootstrap optimism correction. The validation cohort c-statistic was 0.823 (N = 993). The model had good discrimination for left and right CDH, inborn and outborn patients, patients born before and after 2011, and high and low volume centers. The model performed significantly better for postnatally diagnosed patients.

CONCLUSIONS

This study represents proof-of-concept that a risk model can accurately estimate the probability of ECMO use in CDH newborns. This stratification could assist centers as a metric for assessment of ECMO usage and outcomes. Refinement and prospective validation of this model should be carried out prior to clinical application.

LEVEL OF EVIDENCE

3.

Developmental origin and morphogenesis of the diaphragm, an essential mammalian muscle

The diaphragm is a mammalian skeletal muscle essential for respiration and for separating the thoracic and abdominal cavities. Development of the diaphragm requires the coordinated development of muscle, muscle connective tissue, tendon, nerves, and vasculature that derive from different embryonic sources. However, defects in diaphragm development are common and the cause of an often deadly birth defect, Congenital Diaphragmatic Hernia (CDH). Here we comprehensively describe the normal developmental origin and complex spatial-temporal relationship between the different developing tissues to form a functional diaphragm using a developmental series of mouse embryos genetically and immunofluorescently labeled and analyzed in whole mount. We find that the earliest developmental events are the emigration of muscle progenitors from cervical somites followed by the projection of phrenic nerve axons from the cervical neural tube. Muscle progenitors and phrenic nerve target the pleuroperitoneal folds (PPFs), transient pyramidal-shaped structures that form between the thoracic and abdominal cavities. Subsequently, the PPFs expand across the surface of the liver to give rise to the muscle connective tissue and central tendon, and the leading edge of their expansion precedes muscle morphogenesis, formation of the vascular network, and outgrowth and branching of the phrenic nerve. Thus development and morphogenesis of the PPFs is critical for diaphragm formation. In addition, our data indicate that the earliest events in diaphragm development are critical for the etiology of CDH and instrumental to the evolution of the diaphragm. CDH initiates prior to E12.5 in mouse and suggests that defects in the early PPF formation or their ability to recruit muscle are an important source of CDH. Also, the recruitment of muscle progenitors from cervical somites to the nascent PPFs is uniquely mammalian and a key developmental innovation essential for the evolution of the muscularized diaphragm.

Role of ECMO in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is typified morphologically by failure of diaphragmatic development with accompanying lung hypoplasia and persistent pulmonary hypertension of the newborn (PPHN). Patients who have labile physiology and low preductal saturations despite optimal ventilatory and inotropic support may be considered for extracorporeal membrane oxygenation (ECMO). Systematic reviews into the benefits of ECMO in CDH concluded that any benefit is unclear. Few randomised trials exist to demonstrate clear benefit and guide management. However, ECMO may have its uses in those that have reversibility of their respiratory disease. A few centres and networks have demonstrated an increase in survival rate by post hoc analysis (based on a difference in referral patterns with the availability of ECMO) in their series. One issue may be that of careful patient selection with regard to reversibility of pathophysiology. At present, there is no single test or prognostication that predicts reversibility of PPHN and criteria for referral for ECMO is undergoing continued refinement. Overall survival is similar between cannulation modes. There is no consensus on the time limit for ECMO runs. The optimal timing of surgery for patients on ECMO is difficult to definitively establish, but it seems that repair at an early stage (with careful perioperative management) is becoming less of a taboo, and may improve outcome and help with either coming off ECMO or decisions on withdrawal later. The provision of ECMO will continue to be evaluated, and prospective randomised trial are needed to help answer question of patient selection and management.

Seasonality, Epidemiology and Outcome of Congenital Diaphragmatic Hernia in South West of Iran

INTRODUCTION

The pathogenesis of congenital diaphragmatic hernia (CDH) is not clear. Risk factors including environmental factors have been implicated in the pathogenesis of few congenital anomalies. We aimed to assess the effect of season on the incidence of CDH and mortality rate in the southwest of Iran.

MATERIAL AND METHODS

In this retrospective study, the records of 60 patients with CDH who were admitted at Neonatal Intensive Care Unit (NICU) of Imam Khomeini Hospital of Ahvaz, Iran were evaluated.

RESULTS

Assuming that all the neonates born with CDH in the region reach this hospital, overall CDH prevalence rate was 1.09 per 10 000 total births. Conceptions in spring and summer in this region had statistically significantly higher incidence of CDH. Survival rate in the series was 41.6%.

CONCLUSION

Seasonal variation has impact on the incidence of CDH. Mortality rate in neonates with CDH is still very high.

Excessive Reversal of Epidermal Growth Factor Receptor and Ephrin Signaling Following Tracheal Occlusion in Rabbit Model of Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) causes severe pulmonary hypoplasia from herniation of abdominal contents into the thorax. Tracheal occlusion (TO) for human CDH improves survival, but morbidity and mortality remain high, and we do not fully understand the cellular pathways and processes most severely impacted by CDH and TO. We created a left diaphragmatic hernia (DH) in rabbit fetuses with subsequent TO and collected left lung sections for NextGen mRNA sequencing. DH, TO, and DHTO fetuses had comparable body and organ growth to control except for lower lung weights in DH (p<0.05). Of 13,687 expressed genes, DHTO had 687 differentially expressed genes compared to DH, but no other group-group comparison had more than 10. Considering genes in combination, many of the genes reduced in DH were more highly expressed in DHTO than in control. Benchmarking fetal rabbit lung gene expression to published lung development data, both DH and DHTO lungs were more highly correlated with the gene expression of immature lung. DNA synthesis was upregulated in DHTO compared to DH and ribosome and protein synthesis pathways were downregulated. DH reduced total and epithelial cell proliferation by half and two-thirds respectively, and DHTO increased proliferation by 2.5 and 3.4-fold respectively. Signaling pathways downregulated by DH and upregulated in DHTO were epidermal growth factor receptor signaling, ephrin signaling, and cell migration; however, levels of ephrin and EGFR signaling in DHTO exceeded that of control. Identification and inhibition of the ligands responsible for this dysregulated signaling could improve lung development in CDH.

Emergency Corrective Surgery of Congenital Diaphragmatic Hernia With Pulmonary Hypertension: Prolonged Use of Dexmedetomidine as a Pharmacologic Adjunct

INTRODUCTION

Underdevelopment of the lung parenchyma associated with abnormal growth of pulmonary vasculature in neonates with congenital diaphragmatic hernia results in pulmonary hypertension which mandates smooth elective mechanical ventilation in postoperative period, for proper alveolar recruitment and oxygenation, allowing lungs to mature enough for its functional anatomy and physiology. Dexmedetomidine is sympatholytic, reduces pulmonary vascular resistance and exerts sedative and analgesic property to achieve stable hemodynamics during elective ventilation. Neonatal experience with dexmedetomidine has been predominately in the form of short term or procedural use as a sedative.

CASE PRESENTATION

The preliminary clinical experience with pre-induction to 48 hours postoperative use of dexmedetomidine infusion as a pharmacologic adjunct in the emergency corrective surgery of three such neonates are presented.

CONCLUSIONS

Hemodynamics remained virtually stable during the whole procedure and post-operative pain relief and recovery profile were satisfactory. The prolonged infusion was well tolerated with a gradual trend towards improved oxygen saturation. Careful planning of the anesthetic management and the ability to titrate the adjunct utilized for smooth postoperative ventilation are the keys to ameliorate the complications encountered and favorable outcomes achieved in such patients.

Recurrent diaphragmatic hernia: Modifiable and non-modifiable risk factors

RATIONALE

The risk of recurrence of Congenital Diaphragmatic Hernia (CDH) in an era of thoracoscopic surgery is unclear.

OBJECTIVES

(1) estimate the incidence and (2) evaluate the perioperative factors associated with the symptomatic recurrence of CDH.

METHODS

Medical records of CDH infants operated on in the neonatal period at a single-tertiary hospital between January 2000 and January 2013 were retrospectively reviewed.

RESULTS

Of 119 infants with CDH, 34 (28.6%) were excluded: 17 (14.3%) died without recurrence and 17 (14.3%) presented beyond neonatal period or were followed elsewhere. Of 85 survivors, 71 infants had an open repair and 14 had a thoracoscopic repair. Eleven of 85 survivors (13%) developed a recurrence on average 19.8 weeks (range 15-34) after the initial repair. Of 11 recurrences, 6 had an initial thoracoscopic repair and 5 had an open repair (6/14 [43%] vs. 5/71 [7%]; P = 0.002). Two children had multiple recurrences. Statistically significant associations were found between recurrence and the presence of persistent pulmonary hypertension (PPHTN) (P = 0.006), severe PPHTN (P = 0.002), inhaled nitric oxide, or sildenafil use for treatment of PPHTN (P = 0.002), need for perioperative high frequency oscillatory ventilation (HFOV) (P = 0.0006), length of hospital stay (LOS) (P = 0.02), duration of ventilation (P = 0.016), and need for home oxygen (P = 0.003). In multivariate regression analysis both the closure type and home oxygen requirement were statistically significant, independent factors predicting a recurrence (P = 0.04 and 0.02, respectively) but the type of surgery (thoracoscopic vs. open) only approached significance (P = 0.052). The recurrence rate for the seven surgeons who performed at least 5 repairs ranged from 7% to 40%.

CONCLUSIONS

A high survival rate of 85% with a 13% incidence of symptomatic CDH recurrence was demonstrated. Potentially, improved selection of cases for thoracoscopic repair and concentrating the thoracoscopic technique amongst a dedicated team of experienced thoracoscopic surgeons may reduce the rate of recurrence of CDH.

Primary Combined Latissimus Dorsi and Serratus Anterior Flap Repair of Right-Sided Congenital Diaphragmatic Agenesis in a Neonate

Large diaphragmatic defects can be repaired with latissimus dorsi and serratus anterior muscle flaps. We report the first successful primary repair of complete congenital diaphragmatic agenesis using a combination of autologous living bio-tissue and synthetic mesh in a neonate born in the NMC Specialty Hospital in Dubai, United Arab Emirates, in May 2014. Poor Apgar scores, a scaphoid abdomen and absent breath sounds over the right hemithorax were observed at birth. Chest and abdominal X-rays revealed a diaphragmatic hernia. The neonate was stabilised using high-frequency oscillatory ventilation, nitric oxide and sildenafil. The right diaphragm was reconstructed using combined latissimus dorsi and serratus anterior muscle flaps reinforced by a flexible composite mesh. At 12 months old, the infant had normal respiratory function and the diaphragm was intact. No disabilities of the shoulder or scapula were observed. This case indicates that a combination of living tissue and synthetic mesh can be used to reconstruct a functional diaphragm with efficient pleuroperitoneal separation.

Wt1 and β-catenin cooperatively regulate diaphragm development in the mouse

The developing diaphragm consists of various differentiating cell types, many of which are not well characterized during organogenesis. One important but incompletely understood tissue, the diaphragmatic mesothelium, is distinctively present from early stages of development. Congenital Diaphragmatic Hernia (CDH) occurs in humans when diaphragm tissue is lost during development, resulting in high morbidity and mortality postnatally. We utilized a Wilms Tumor 1 (Wt1) mutant mouse model to investigate the involvement of the mesothelium in normal diaphragm signaling and development. Additionally, we developed and characterized a Wt1(CreERT2)-driven β-catenin loss-of-function model of CDH after finding that canonical Wnt signaling and β-catenin are reduced in Wt1 mutant mesothelium. Mice with β-catenin loss or constitutive activation induced in the Wt1 lineage are only affected when tamoxifen injection occurs between E10.5 and E11.5, revealing a critical time-frame for Wt1/ β-catenin activity. Conditional β-catenin loss phenocopies the Wt1 mutant diaphragm defect, while constitutive activation of β-catenin on the Wt1 mutant background is sufficient to close the diaphragm defect. Proliferation and apoptosis are affected, but primarily these genetic manipulations appear to lead to a change in normal diaphragm differentiation. Our data suggest a fundamental role for mesothelial signaling in proper formation of the diaphragm.

The role of vertebrate nonmuscle Myosin II in development and human disease

Three different genes each located on a different chromosome encode the heavy chains of nonmuscle myosin II in humans and mice. This review explores the functional consequences of the presence of three isoforms during embryonic development and beyond. The roles of the various isoforms in cell division, cell-cell adhesion, blood vessel formation and neuronal cell migration are addressed in animal models and at the cellular level. Particular emphasis is placed on the role of nonmuscle myosin II during cardiac and brain development, and during closure of the neural tube and body wall. Questions addressed include the consequences on organ development, of lowering or ablating a particular isoform as well as the effect of substituting one isoform for another, all in vivo. Finally the roles of the three isoforms in human diseases such as cancer as well as in syndromes affecting a variety of organs in humans are reviewed.

Neurodevelopmental outcome in Congenital Diaphragmatic Hernia survivors during the first three years

OBJECTIVE

To determine neurodevelopmental outcome in Congenital Diaphragmatic Hernia (CDH) survivors during the first three years of life.

METHODS

Admitted CDH patients were assessed at the age of 12 (n=18) and 36 months (n=15) using the Bayley Scales of Infant and Toddler Development Third Edition. Neurodevelopmental results of CDH patients were compared with published norms and with a healthy matched control group.

RESULTS

At 12 months, receptive language was mildly delayed in 6% of patients and 6% of patients demonstrated mildly delay in expressive language and gross motor skills. Eighteen percent of CDH patients had severely delayed scores for gross motor skills. At 36 months, expressive language scores were mildly delayed in 21% of patients. When compared to the control group, CDH patients had similar neurodevelopmental scores at 12 and 36 months of age.

CONCLUSION

CDH is not necessarily associated with impaired neurodevelopmental outcomes during the first three years of life.

SUMMARY

The aim of this study was to describe neurodevelopmental outcomes in Congenital Diaphragmatic Hernia (CDH) survivors. At 12 months, three (18%) patients had severely delayed scores for gross motor skills. At 36 months, expressive language scores were mildly delayed in three (21%) patients. Neurodevelopmental outcomes of CDH patients were no different to healthy matched controls at 12 and 36 months.

Exome sequencing identifies a recessive PIGN splice site mutation as a cause of syndromic congenital diaphragmatic hernia. Eur J Med Genet. 2014;57:487-493. [PMID: 24852103 DOI: 10.1016/j.ejmg.2014.05.001]

Using exome sequencing we identify a homozygous splice site mutation in the PIGN gene in a foetus with multiple congenital anomalies including bilateral diaphragmatic hernia, cardiovascular anomalies, segmental renal dysplasia, facial dysmorphism, cleft palate, and oligodactyly. This finding expands the phenotypic spectrum associated with homozygous loss of function mutations in PIGN, and adds further support for defective GPI anchor biosynthesis as a cause of developmental abnormalities. We demonstrate that exome sequencing is a valuable approach for the identification of a genetic cause in sporadic cases of multiple congenital anomalies (MCA) due to inherited mutations.

A simplified formula using early blood gas analysis can predict survival outcomes and the requirements for extracorporeal membrane oxygenation in congenital diaphragmatic hernia

The aims of this study were to investigate whether early arterial blood gas analysis (ABGA) could define the severity of disease in infants with congenital diaphragmatic hernia (CDH). We conducted a retrospective study over a 21-yr period of infants diagnosed with CDH. Outcomes were defined as death before discharge, and extracorporeal membrane oxygenation requirements (ECMO) or death. A total 114 infants were included in this study. We investigated whether simplified prediction formula [PO2-PCO2] values at 0, 4, 8, and 12 hr after birth were associated with mortality, and ECMO or death. The area under curve (AUC) of receiver operating characteristic curve was used to determine the optimum ABGA values for predicting outcomes. The value of [PO2-PCO2] at birth was the best predictor of mortality (AUC 0.803, P < 0.001) and at 4 hr after birth was the most reliable predictor of ECMO or death (AUC 0.777, P < 0.001). The value of [PO2-PCO2] from ABGA early period after birth can reliably predict outcomes in infants with CDH.