Incidence, predictors and outcomes of congenital diaphragmatic hernia: a population-based study of 32 million births in the United States

Congenital diaphragmatic hernia with intrathoracic kidney: case report, review of the literature, and strategy for treatment in neonates and infants

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a rare developmental defect in the diaphragm, occurring in 2 in 10,000 births. Herniation of intraperitoneal organs through the diaphragmatic opening is always present, however few cases mention the herniation of retroperitoneal organs, such as a kidney. Due to the rarity of this condition, the optimal treatment strategy remains unclear.

METHODS

A PubMed search was conducted, gathering all published reports of CDH with intrathoracic herniation of the kidney. Cases of isolated intrathoracic kidney without CDH and cases of traumatic hernia were excluded. Patients who underwent surgical repair before the age of 5 years were included for further analysis.

RESULTS

Thirty-seven cases were found from 1970 to 2022. The approach used for surgical repair was not mentioned in 55.6% of cases. 52.9% of the remaining patients were treated through laparotomy, whereas in 23.5% a thoracoscopy was performed. A primary repair of the hernia was performed in 88.6%. A hernia sac was noted in 70%. Most patients had a normal origin of the renal vessels and reduction of the intrathoracic kidney was achieved in 78.8%. Moreover, we report a case of CDH with intrathoracic kidney treated through thoracoscopic repair.

CONCLUSION

A thoracoscopic approach is effective for the treatment of CDH with an intrathoracic kidney case with an associated intrathoracic kidney. A therapeutic strategy for CDH with intrathoracic kidney is suggested based on data from published cases.

Disparities in Healthcare Utilization: An Analysis of Disease Specific and Patient Level Factors in a Congenital Diaphragmatic Hernia Clinic

OBJECTIVES

Our study examines if the disease severity profile of our Congenital Diaphragmatic Hernia (CDH) patient cohort adherent to long-term follow-up differs from patients lost to follow-up after discharge and examines factors associated with health care utilization.

METHODS

Retrospective review identified CDH survivors born 2005-2019 with index repair at our institution. Primary outcome was long-term follow-up status: "active" or "inactive" according to clinic guidelines. Markers of CDH disease severity including CDH defect classification, oxygen use, tube feeds at discharge, and sociodemographic factors were examined as exposures.

RESULTS

Of the 222 included patients, median age [IQR] was 10.2 years [6.7-14.3], 61% male, and 57 (26%) were insured by Medicaid. Sixty-three percent (139/222) of patients were adherent to follow-up. Seventy-six percent of patients discharged on tube feeds had active follow-up compared to 55% of patients who were not, with similar findings for oxygen at discharge (76% vs. 55%). Kaplan-Meier analysis showed patients with smaller defect size had earlier attrition compared to patients with larger defect size. Other race (Hispanic, Asian, Middle Eastern) patients had 2.87 higher odds of attrition compared to white patients (95% CI 1.18-7.0). Medicaid patients had 2.64 higher odds of attrition compared to private insurance (95% CI 1.23-5.66).

CONCLUSION

Loss to follow-up was associated with race and insurance type. Disease severity was similar between the active and inactive clinic cohorts. Long-term CDH clinic publications should examine attrition to ensure reported outcomes reflect the discharged population. This study identified important factors to inform targeted interventions for follow-up adherence.

LEVEL OF EVIDENCE

Level III.

Prenatal diagnostic and intervention considerations in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a life-threatening birth defect with significant morbidity and mortality. The prenatal management of a pregnancy with a fetus affected with CDH is complex and requires a multi-disciplinary team approach. An improved understanding of prenatal diagnosis and management is essential to developing strategies to optimize outcomes for these patients. In this review, we explore the current knowledge on diagnosis, severity stratification, prognostic prediction, and indications for fetal intervention in the fetus with CDH.

Epidemiology of congenital diaphragmatic hernia among 24 million Chinese births: a hospital-based surveillance study

BACKGROUND

The prevalence of congenital diaphragmatic hernia (CDH) varies across countries, with limited information available on its epidemiology in China. Our study aimed to investigate the prevalence, time trends, and perinatal outcomes of CDH in China, as well as its associated malformations and potential associations with maternal and infant characteristics.

METHODS

This study included all birth and CDH cases from the Chinese Birth Defects Monitoring Network between 2007 and 2019, with CDH cases classified as either isolated or associated. We employed the joinpoint regression model to calculate the trends of prevalence and the annual percent change, with Poisson regression used for adjusted prevalence rate ratios. A P value ≤ 0.05 was considered statistically significant.

RESULTS

A total of 4397 CDH cases were identified among 24,158,029 births in the study period, yielding prevalence rates of 1.82, 1.13 and 0.69 per 10,000 for overall, isolated, and associated CDH, respectively. The prevalence of each type of CDH increased over time. The prevalence of overall CDH varied significantly by infant sex (male vs. female, 1.91/10,000 vs. 1.63/10,000), maternal residence (urban vs. rural, 2.13/10,000 vs. 1.45/10,000), maternal age (< 20 years, 1.31/10,000; 20-24 years, 1.63/10,000; 25-29 years, 1.80/10,000; 30-34 years, 1.87/10,000; ≥ 35 years, 2.22/10,000), and geographic region (central, 1.64/10,000; east, 2.45/10,000; west, 1.37/10,000). Cardiovascular anomalies were the most common malformations associated with CDH. Infants with associated CDH had a higher risk of premature birth and perinatal death than those with isolated CDH.

CONCLUSION

The increasing prevalence and high perinatal mortality rate of CDH highlight the need for further etiological, epidemiological, and clinical studies among the Chinese population. Video Abstract.

Rescuing lung development through embryonic inhibition of histone acetylation

A major barrier to the impact of genomic diagnosis in patients with congenital malformations is the lack of understanding regarding how sequence variants contribute to disease pathogenesis and whether this information could be used to generate patient-specific therapies. Congenital diaphragmatic hernia (CDH) is among the most common and severe of all structural malformations; however, its underlying mechanisms are unclear. We identified loss-of-function sequence variants in the epigenomic regulator gene SIN3A in two patients with complex CDH. Tissue-specific deletion of Sin3a in mice resulted in defects in diaphragm development, lung hypoplasia, and pulmonary hypertension, the cardinal features of CDH and major causes of CDH-associated mortality. Loss of SIN3A in the lung mesenchyme resulted in reduced cellular differentiation, impaired cell proliferation, and increased DNA damage. Treatment of embryonic Sin3a mutant mice with anacardic acid, an inhibitor of histone acetyltransferase, reduced DNA damage, increased cell proliferation and differentiation, improved lung and pulmonary vascular development, and reduced pulmonary hypertension. These findings demonstrate that restoring the balance of histone acetylation can improve lung development in the Sin3a mouse model of CDH.

Prognostic value of echocardiographic parameters in congenital diaphragmatic hernia: a systematic review and meta-analysis

BACKGROUND

Prognostication of mortality and decision to offer extracorporeal membrane oxygenation (ECMO) treatment in infants with congenital diaphragmatic hernia (CDH) can inform clinical management.

OBJECTIVE

To summarise the prognostic value of echocardiography in infants with CDH.

METHODS

Electronic databases Ovid MEDLINE, Embase, Scopus, CINAHL, the Cochrane Library and conference proceedings up to July 2022 were searched. Studies evaluating the prognostic performance of echocardiographic parameters in newborn infants were included. Risk of bias and applicability were assessed using the Quality Assessment of Prognostic Studies tool. We used a random-effect model for meta-analysis to compute mean differences (MDs) for continuous outcomes and relative risk (RR) for binary outcomes with 95% CIs. Our primary outcome was mortality; secondary outcomes were need for ECMO, duration of ventilation, length of stay, and need for oxygen and/or inhaled nitric oxide.

RESULTS

Twenty-six studies were included that were of acceptable methodological quality. Increased diameters of the right and left pulmonary arteries at birth (mm), MD 0.95 (95% CI 0.45 and 1.46) and MD 0.79 (95% CI 0.58 to 0.99), respectively) were associated with survival. Left ventricular (LV) dysfunction, RR 2.40, (95% CI 1.98 to 2.91), right ventricular (RV) dysfunction, RR 1.83 (95% CI 1.29 to 2.60) and severe pulmonary hypertension (PH), RR 1.69, (95% CI 1.53 to 1.86) were associated with mortality. Left and RV dysfunctions, RR 3.30 (95% CI 2.19 to 4.98) and RR 2.16 (95% CI 1.85 to 2.52), respectively, significantly predicted decision to offer ECMO treatment. Limitations are lack of consensus on what parameter is optimal and standardisation of echo assessments.

CONCLUSIONS

LV and RV dysfunctions, PH and pulmonary artery diameter are useful prognostic factors among patients with CDH.

Survival in very preterm infants with congenital diaphragmatic hernia and association with prenatal imaging markers: A retrospective cohort study

OBJECTIVES

To describe the outcomes of preterm born infants with congenital diaphragmatic hernia (CDH; ≤32.0 weeks of gestation) and the associations between prenatal imaging markers and survival.

DESIGN

Retrospective cohort study.

SETTING

Multicentre study in large referral centres.

POPULATION

Infants with an isolated unilateral CDH, live born at 32.0 weeks or less of gestation, between January 2009 and January 2020.

METHODS

Neonatal outcomes were evaluated for infants that were expectantly managed during pregnancy and infants that underwent fetoscopic endoluminal tracheal occlusion (FETO) therapy, separately. We evaluated the association between prenatal imaging markers and survival to discharge. Prenatal imaging markers included observed to expected lung-to-head ratio (o/e LHR), side of the defect, liver position, stomach position grade, and observed to expected total fetal lung volume (o/e TFLV).

MAIN OUTCOME MEASURE

Survival to discharge.

RESULTS

We included 53 infants born at 30+4 (interquartile range 29+1 -31+2 ) weeks. Survival in fetuses expectantly managed during pregnancy was 48% (13/27) in left-sided CDH and 33% (2/6) in right-sided CDH. Survival in fetuses that underwent FETO therapy was 50% (6/12) in left-sided CDH and 25% (2/8) in right-sided CDH. The o/e LHR at baseline was positively associated with survival in cases expectantly managed during pregnancy (odds ratio [OR] 1.20, 95% CI 1.07-1.42, p < 0.01), but not in cases that received FETO therapy (OR 1.01, 95% CI 0.88-1.15, p = 0.87). Stomach position grade (p = 0.03) and o/e TFLV were associated with survival (p = 0.02); liver position was not (p = 0.13).

CONCLUSIONS

In infants with CDH born at or before 32 weeks of gestation, prenatal imaging markers of disease severity were associated with postnatal survival.

Dynamics of pulmonary hypertension severity in the first 48 h in neonates with prenatally diagnosed congenital diaphragmatic hernia

Introduction

Pulmonary hypertension (PH) is one of the major contributing factors to the high morbidity and mortality in neonates with congenital diaphragmatic hernia (CDH). The severity and duration of postnatal PH are an established risk factor for patient outcome; however, the early postnatal dynamics of PH have not been investigated. This study aims to describe the early course of PH in CDH infants, and its relation to established prognostic markers and outcome measures.

Methods

We performed a monocentric retrospective review of neonates with prenatally diagnosed CDH, who received three standardized echocardiographic examinations at 2-6 h, 24, and 48 h of life. The degree of PH was graded as one of three categories: mild/no, moderate, or severe PH. The characteristics of the three groups and their course of PH over 48 h were compared using univariate and correlational analyses.

Results

Of 165 eligible CDH cases, initial PH classification was mild/no in 28%, moderate in 35%, and severe PH in 37%. The course of PH varied markedly based on the initial staging. No patient with initial no/mild PH developed severe PH, required extracorporeal membrane oxygenation (ECMO)-therapy, or died. Of cases with initial severe PH, 63% had persistent PH at 48 h, 69% required ECMO, and 54% died. Risk factors for any PH included younger gestational age, intrathoracic liver herniation, prenatal fetoscopic endoluminal tracheal occlusion (FETO)-intervention, lower lung to head ratio (LHR), and total fetal lung volume (TFLV). Patients with moderate and severe PH showed similar characteristics, except liver position at 24- (p = 0.042) and 48 h (p = 0.001), mortality (p = 0.001), and ECMO-rate (p = 0.035).

Discussion

To our knowledge, this is the first study to systematically assess the dynamics of PH in the first postnatal 48 h at three defined time points. CDH infants with initial moderate and severe PH have a high variation in postnatal PH severity over the first 48 h of life. Patients with mild/no PH have less change in PH severity, and an excellent prognosis. Patients with severe PH at any point have a significantly higher risk for ECMO and mortality. Assessing PH within 2-6 h should be a primary goal in the care for CDH neonates.

Factors contributing to mortality in neonates with congenital diaphragmatic hernia and eventration

Introduction

Despite all the advances, the mortality rate of congenital diaphragmatic hernia (CDH) ranges from 30% to 60% for isolated CDH and as high as 89% when they are associated with additional structural or chromosomal anomalies. Hence, a study was conducted to evaluate the factors contributing to the mortality of neonates treated for CDH or the eventration of diaphragm.

Materials and Methods

A retrospective study was conducted in the department of paediatric surgery at a tertiary centre. The neonates admitted with a diagnosis of CDH or eventration requiring surgery, between March 2013 and March 2021, were included in the study.

Results

A total of 123 neonates were included in the study. The variables, earlier median age at presentation (1 [1-23] vs. 3 [1-28]; P < 0.001; Mann-Whitney U-test), preterm birth (10/79 vs. 0/44; P = 0.01; Fischer's exact test), inborn (68/79 vs. 27/44; P = 0.002; Chi-square test), weight ≤2 kg (18/79 vs. 1/44; P = 0.003; Chi-square test), central cyanosis at presentation (21/79 vs. 1/44; P < 0.001; Chi-square test), antenatal detection (47/79 vs. 14/44; P = 0.003; Chi-square test) and earlier mean age at surgery (3.66 ± 1.47 vs. 7.66 ± 6.88; P < 0.001; Independent sample t-test) were associated with increased mortality. On multinominal logistic regression analysis, the factors preterm (odd's Ratio [OR] =4.735; P = 0.03), weight ≤2 kg (OR = 5.081; P = 0.02), central cyanosis at presentation (OR = 6.969; P = 0.008) and antenatal detection (OR = 7.471; P = 0.006) were found to be independently associated with increased mortality in CDH/eventration.

Conclusion

The factors: prematurity, weight <2 kg, cyanosis at presentation and antenatal diagnosis were independently associated with increased mortality in neonates with CDH/eventration requiring surgery.

Connecting clinical, environmental, and genetic factors point to an essential role for vitamin A signaling in the pathogenesis of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a developmental disorder that results in incomplete diaphragm formation, pulmonary hypoplasia, and pulmonary hypertension. Although a variety of genes have been linked to its etiology, CDH is not a monogenetic disease, and the cause of the condition is still unclear in the vast majority of clinical cases. By comparing human clinical data and experimental rodent data from the literature, we present clear support demonstrating the importance of vitamin A (vitA) during the early window of pregnancy when the diaphragm and lung are forming. Alteration of vitA signaling via dietary and genetic perturbations can create diaphragmatic defects. Unfortunately, vitA deficiency is chronic among people of child-bearing age, and this early window of diaphragm development occurs before many might be aware of pregnancy. Furthermore, there is an increased demand for vitA during this critical period, which exacerbates the likelihood of deficiency. It would be beneficial for the field to further investigate the connections between maternal vitA and CDH incidence, with the goal of determining vitA status as a CDH risk factor. Regular clinical monitoring of vitA levels in child-bearing years is a tractable method by which CDH outcomes could be prevented or improved.

Analgesia, Sedation, and Neuromuscular Blockade in Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

The aim of this study was to describe the use, duration, and intercenter variation of analgesia and sedation in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This is a retrospective analysis of analgesia, sedation, and neuromuscular blockade use in neonates with CDH. Patient data from 2010 to 2016 were abstracted from the Children's Hospitals Neonatal Database and linked to the Pediatric Health Information System. Patients were excluded if they also had non-CDH conditions likely to affect the use of the study medications.

RESULTS

A total of 1,063 patients were identified, 81% survived, and 30% were treated with extracorporeal membrane oxygenation (ECMO). Opioid (99.8%), sedative (93.4%), and neuromuscular blockade (87.9%) use was common. Frequency of use was higher and duration was longer among CDH patients treated with ECMO. Unadjusted duration of use varied 5.6-fold for benzodiazepines (median: 14 days) and 7.4-fold for opioids (median: 16 days). Risk-adjusted duration of use varied among centers, and prolonged use of both opioids and benzodiazepines ≥5 days was associated with increased mortality (p < 0.001) and longer length of stay (p < 0.001). Use of sedation or neuromuscular blockade prior to or after surgery was each associated with increased mortality (p ≤ 0.01).

CONCLUSION

Opioids, sedatives, and neuromuscular blockade were used commonly in infants with CDH with variable duration across centers. Prolonged combined use ≥5 days is associated with mortality.

KEY POINTS

· Use of analgesia and sedation varies across children's hospital NICUs.. · Prolonged opioid and benzodiazepine use is associated with increased mortality.. · Postsurgery sedation and neuromuscular blockade are associated with mortality..

Perioperative Improvement in Pulmonary Function in Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

The objective of this study was to compare serial changes in pulmonary function in contemporary infants with congenital diaphragmatic hernia managed with a gentle ventilation approach.

STUDY DESIGN

Observational cohort, single-center study of infants ≥35^0/7 weeks gestation at delivery with congenital diaphragmatic hernia. Functional residual capacity (FRC), passive respiratory compliance, and passive respiratory resistance were measured presurgical and postsurgical repair and within 2 weeks of discharge. A 1-way analysis of variance for repeated measures was used to evaluate the change in FRC, passive respiratory compliance, and passive respiratory resistance over these repeated measures.

RESULTS

Twenty-eight infants were included in the analysis with a mean gestational age of 38.3 weeks and birth weight of 3139 g. We found a significant increase in FRC across the 3 time points (mean in mL/kg [SD]: 10.9 [3.6] to 18.5 [5.2] to 24.2 [4.4]; P < .0001). There was also a significant increase in passive respiratory compliance and decrease in passive respiratory resistance. In contrast to a previous report, there were survivors in the current cohort with a preoperative FRC of <9 mL/kg. The mean FRC measured at discharge was in the range considered within normal limits. Sixteen infants had prenatal measurements of the lung-to-head ratio, but there was no relationship between the lung-to-head ratio and preoperative or postoperative FRC measurements.

CONCLUSIONS

Infants with congenital diaphragmatic hernia demonstrate significant increases in FRC and improvements in respiratory mechanics measured preoperatively and postoperatively and at discharge. We speculate these improvements are due to the surgical resolution of the mechanical obstruction to lung recruitment and that after achieving preoperative stability, repair should not be delayed given these demonstrable postoperative improvements.

The role of genes and environment in the etiology of congenital diaphragmatic hernias

Structural birth defects are a common cause of abnormalities in newborns. While there are cases of structural birth defects arising due to monogenic defects or environmental exposures, many birth defects are likely caused by a complex interaction between genes and the environment. A structural birth defect with complex etiology is congenital diaphragmatic hernias (CDH), a common and often lethal disruption in diaphragm development. Mutations in more than 150 genes have been implicated in CDH pathogenesis. Although there is generally less evidence for a role for environmental factors in the etiology of CDH, deficiencies in maternal vitamin A and its derivative embryonic retinoic acid are strongly associated with CDH. However, the incomplete penetrance of CDH-implicated genes and environmental factors such as vitamin A deficiency suggest that interactions between genes and environment may be necessary to cause CDH. In this review, we examine the genetic and environmental factors implicated in diaphragm and CDH development. In addition, we evaluate the potential for gene-environment interactions in CDH etiology, focusing on the potential interactions between the CDH-implicated gene, Gata4, and maternal vitamin A deficiency.

The Genomics of Congenital Diaphragmatic Hernia: A 10-Year Retrospective Review

OBJECTIVE

To evaluate genetic testing use in infants with congenital diaphragmatic hernia (CDH) over the past decade to better inform future practices and individualize prognostication and management.

STUDY DESIGN

A retrospective cohort study was performed of all infants with CDH enrolled in the Pulmonary Hypoplasia Program at Children's Hospital of Philadelphia, born between January 2011 and February 2021. For each infant, demographic information, prenatal and postnatal history, and genetic testing were reviewed.

RESULTS

The charts of 411 infants were analyzed. Overall, 22% (n = 89) were complex/syndromic and 78% (n = 322) were isolated/nonsyndromic. Mortality was significantly higher in complex/syndromic infants (P < .001) and in infants with diagnostic genetic testing (P < .001). Microarray was diagnostic in 9% (n = 34/399) and exome sequencing was diagnostic in 38% (n = 15/39). Genetic testing was diagnostic in 57% (n = 51/89) of complex/syndromic infants, but in only 2% of isolated/nonsyndromic infants (n = 8/322). Overall, genetic testing was diagnostic in 14% (n = 56).

CONCLUSIONS

The high diagnostic rate in this cohort highlights the utility of comprehensive genetic testing in infants with CDH. However, 43% of complex/syndromic and 98% of isolated/nonsyndromic infants do not have a genetic etiology identified. This finding underscores the need for additional genetic and genomic studies (eg, whole genome, RNA sequencing) to identify novel genes and mutational mechanisms (single genes, regulatory elements, complex traits) that will allow for improved diagnostic rates and ultimately individualized management of infants with CDH.

Maternal cigarette smoking and alcohol consumption and congenital diaphragmatic hernia

Background

Congenital diaphragmatic hernia (CDH) occurs when abnormal diaphragm development allows herniation of abdominal organs into the thoracic cavity. Its etiopathogenesis is not well understood, but cigarette smoking and alcohol exposure may impact diaphragm development. Using data from a large, population‐based case–control study, we examined associations between maternal cigarette smoking and alcohol consumption and CDH in offspring.

Methods

We analyzed maternal interview reports of cigarette smoking and alcohol consumption during early pregnancy for 831 children with CDH and 11,416 children without birth defects with estimated dates of delivery during 1997–2011. Generalized linear mixed effects models with a random intercept for study site were used to estimate associations between measures of exposure to smoking (any, type, frequency, duration) and alcohol (any, quantity, frequency, variability, type) for all CDH combined and selected subtypes (Bochdalek and Morgagni).

Results

Mothers of 280 (34.0%) case and 3,451 (30.3%) control children reported early pregnancy exposure to cigarette smoking. Adjusted odds ratios for all CDH were increased for any (1.3; 95% confidence interval 1.1–1.5), active (1.3, 1.0–1.7), and passive (1.4, 1.1–1.7) smoking. Early pregnancy alcohol consumption was reported by mothers of 286 (34.9%) case and 4,200 (37.0%) control children; odds were near the null for any consumption (0.9, 0.8–1.1) and consumption with (0.9, 0.7, 1.1) or without (0.9, 0.8, 1.1) binging. Estimates for smoking and alcohol tended to be higher for Bochdalek CDH and Morgagni CDH than those for all CDH.

Conclusions

Findings suggest that maternal early pregnancy exposure to cigarette smoking, but less so to alcohol consumption, contributes to CDH. These findings need to be replicated in additional large studies that use systematic case ascertainment and classification, detailed exposure assessment, and examine subtype‐specific associations.

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.

High altitude simulation testing in patients with congenital diaphragmatic hernia

AIM OF STUDY

Congenital Diaphragmatic Hernia (CDH) is associated with lung hypoplasia and pulmonary hypertension. Many patients receive care in specialty centers requiring air travel upon discharge and for subsequent follow-up care. Premature infants can experience significant hypoxia in flight, but this has not been studied in the CDH population. This report describes our center's experience with simulated altitude testing among CDH patients.

METHODS

In a single center retrospective cohort study, CDH patients who underwent a High Altitude Simulation Test (HAST) from 2006 to 2019 were analyzed. HAST simulates increased altitude by reducing oxygen tension to an FIO2 of 0.15. Patients were tested only when flight was anticipated. Patients requiring oxygen were challenged on their baseline requirement. To pass, patients had to maintain oxygen saturation > 90%, and 94% if diagnosed with pulmonary hypertension. Supplemental oxygen was titrated as needed to achieve this goal.

RESULTS

Of twenty patients tested, only six (30%) passed on their first attempt. Ten (50%) eventually passed, after an average of 3.2 additional attempts over 1.8 years. No patient passed initially who utilized ECMO support, diaphragmatic agenesis, or had elevated right ventricular pressure on echocardiogram. All patients achieved the targeted SpO2 with supplemental oxygen.

CONCLUSION

CDH patients experience hypoxia when exposed to the simulated hypobaric nature of air travel and therefore may become hypoxic in flight, requiring oxygen supplementation. Disease severity seems to correlate with risk of in-flight hypoxia. This data suggests that CDH patients should be screened to assess their need for supplemental oxygen to ensure safe air travel.

LEVEL OF EVIDENCE

Level 4 case series.

Right Bochdalek congenital diaphragmatic hernia: a tertiary center's experience over 13 years

Background

Right Bochdalek congenital diaphragmatic hernia (RB-CDH) is far less common than left Bochdalek congenital diaphragmatic hernia, accounting for only 13% of cases. There are limited published data on the outcomes and survival rate of RB-CDH.

We aimed at investigating the clinical characteristics and analyzing the risk factors of survival in neonates with RB-CDH treated in our center over a period of 13 years.

Results

Fifteen infants with RB-CDH were identified. Most of the patients were full term (74%). The mean birth weight was 2.90± 0.72 kg. The ratio of male to female was 2:1. The mean APGAR score at 1 min was 5.31±2.34, and 7.30±1.59 at 5 min. Ten patients (67%) were imaged by antenatal ultrasound. Eleven patients (73.33%) survived to go for surgical repair. The hernia sac was found in 5 patients (45%). Most hernial defects were closed in a primary fashion. The mean age at the operative repair was 8.11±9.90 days. The average NICU stay for all patients was 40.47±50.38 days. The mean follow-up period was 20.45±9.34 months. Three patients had postoperative complications. The total survival rate in neonates with RB-CDH was 9/15 (60%). Nine out of 11 (82%) neonates survived after surgical repair. Four patients (27%) died before surgical repair. Ventilation-related bilateral pneumothorax was a contributing cause of death in three patients. Birth weight was found lower in the non-survivor’s group (P < 0.05). Moreover, the degree of pulmonary hypertension was more severe among non-survivors. No statistical significance was observed between other variables and mortality.

Conclusion

We found that low birth weight and the presence of severe PHTN were risk factors for mortality in neonates with RB-CDH. These results are in line with previous studies on prognostic factors in CDH. Ventilator-related pneumothorax appears to be a significant contributing cause of death. Long-term follow-up studies of infants born with RB-CDH are needed as small number of cases limits large-volume RB-CDH studies.

Magnetic Resonance Imaging Assessment of Pulmonary Vascularity in Infants with Congenital Diaphragmatic Hernia: A Novel Tool for Direct Assessment of Severity of Pulmonary Hypertension and Hypoplasia

OBJECTIVES

To assess the feasibility of magnetic resonance imaging (MRI) for postnatal assessment of pulmonary vascularity in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

Infants with prenatally diagnosed CDH (n = 24) received postnatal pulmonary MRI. Infants with nonpulmonary birth defects served as controls (n = 5). Semiautomatic segmentation was performed to obtain total vascular volume using time of flight images to assess vascularity.

RESULTS

Average vascular density (vascular volume/lung volume) in control infants was 0.23 ± 0.06 mm³/mm³ compared with 0.18 ± 0.06 mm³/mm³ in infants with CDH is (P = .09). When stratified further based on CDH severity, the difference between control infants and moderate CDH group was statistically significant. (0.23 mm³/mm³ vs 0.15 mm³/mm³, P = .01). Ipsilateral vascular density on MRI in infants with CDH significantly correlated with the prenatal pulmonary hypertensive index (P = .0004, Spearman R = +0.87) and with number of days on mechanical ventilation (P = .04, Spearman R = -0.44), total days on inhaled nitric oxide (P = .02, Spearman R = -0.47), use of epoprostenol for acute pulmonary hypertension (PH) (0.14 mm³/mm³ vs 0.20 mm³/mm³, P = .005), and use of sildenafil for chronic PH (0.15 mm³/mm³ vs 0.19 mm³/mm³, P = .03).

CONCLUSIONS

Our results suggest that postnatal pulmonary vascularity assessed by MRI strongly correlates with prenatal and postnatal markers of PH severity and that pulmonary vascularity may serve as a direct measure of pulmonary vascular hypoplasia in infants with CDH.

Achieving adequate growth in infants with congenital diaphragmatic hernia prior to discharge

BACKGROUND/PURPOSE

To evaluate the enteral feeding requirements, including caloric provisions, of infants with CDH in relation to growth patterns.

METHODS

A retrospective observational study was conducted on infants with CDH between August 2012 and March 2017. Electronic medical records were reviewed to extract detailed infant feeding data and anthropometric measurements at monthly intervals until discharge. Statistical methods of analysis included generalized linear models, Pearson correlation coefficient, Analysis of variance (ANOVA), Kruskal-Wallis, Wilcoxon rank sum, and Fisher's Exact tests.

RESULTS

Among 149 infants with CDH, 45% (n = 67) met criteria for malnutrition at discharge. Maternal human milk (HM) was initiated in 95% of infants (n = 142) and continued in 79% of infants (n = 118) at discharge. Overall, 50% received fortification of feeds, including 60% (n = 89) of formula fed infants compared to only 21% (n = 31) of HM fed infants (p<0.001). Infants fed formula had lower weight-for-length z-scores at discharge compared to those fed HM.

CONCLUSIONS

Infants receiving HM demonstrated improved growth compared to formula fed infants. However, higher calorie feeding regimens need to be initiated earlier to improve growth velocity. Prompt recognition of malnutrition and growth failure with aggressive supplementation may improve the overall growth of infants with CDH and has the potential to improve long term neurodevelopmental outcomes.

Primary contributors to gastrostomy tube placement in infants with Congenital Diaphragmatic Hernia

OBJECTIVE

To identify factors associated with gastrostomy tube (GT) placement in infants with congenital diaphragmatic hernia (CDH).

METHODS

Retrospective cohort study of 114 surviving infants with CDH at a single tertiary care neonatal intensive care unit from 2010-2019. Prenatal, perinatal and postnatal characteristics were compared between patients who were discharged home with and without a GT. Prenatal imaging was available for 50.9% of the cohort. Logistic regression was used to assess the association between GT placement and pertinent clinical factors. ROC curves were generated, and Youden's J statistic was used to determine optimal predictive cutoffs for continuous variables. Elastic net regularized regression was used to identify variables associated with GT placement in multivariable analysis.

RESULTS

GT was placed in 43.9% of surviving infants with CDH. Prenatal variables predictive of GT placement were percent predicted lung volume (PPLV) <21%, total lung volume (TLV) <30 ml, lung-head ratio (LHR) <1.2 or observed to expected LHR (O/E LHR) <55%. Infants who required a GT were diagnosed earlier prenatally (23.6 ± 3.4 vs. 26.4 ± 5.6 weeks). Patients whose stomach was above the diaphragm on prenatal ultrasound (up) had a higher odds of GT placement compared to those with stomachs below the diaphragm (down) position by a factor of 2.9 (95% CI: 1.25, 7.1); p = 0.0154. Postnatally, infants with GT had lower Apgar scores at 1 and 5 min, longer lengths of stay and higher proportion of flap closures. Infants with a type C or D defect and extracorporeal membrane oxygenation (ECMO) were associated with increased odds of needing a GT. Postnatal association included being NPO for >12 days, need for transpyloric (TP) feeds for >10 days, >14 days to transition to a 30 min bolus feed, presence of gastro-esophageal reflux (GER), chronic lung disease and pulmonary hypertension. In multivariable analysis, duration of NPO, time to TP feeds, transition to 30 min bolus feeds remained significantly associated with GT placement after adjusting for severity of pulmonary hypertension (PH), GER diagnosis and sildenafil treatment.

CONCLUSION

Identification of risk factors associated with need for long-term feeding access may improve timing of GT placement and prevent prolonged hospitalization related to feeding issues.

LEVEL OF EVIDENCE RATING

Level II (Retrospective Study).

Optimal timing of delivery for pregnancies with prenatally diagnosed congenital diaphragmatic hernia: a propensity-score analysis using the inverse probability of treatment weighting

OBJECTIVE

To evaluate the optimal timing of neonates with prenatally diagnosed congenital diaphragmatic hernia (CDH).

METHODS

Data from a retrospective cohort study conducted by the Japanese CDH Study Group between 2011 and 2018 were divided into two groups according to delivery timing: 36-37 and 38-41 weeks of gestation (wg). Death before 90 days as the primary outcome and the duration of hospitalization, oxygen therapy and tube feeding at discharge as the secondary outcomes were analyzed with generalized linear model applying inverse probability of treatment weighting method. We also performed layered analysis according to stomach position.

RESULT

Among 493 neonates with prenatally diagnosed, isolated and left CDH, 237 were born at 38-41wg. The duration of hospitalization was significantly shorter in those born at 38-41wg, especially among those with stomach malposition, and the other outcomes showed no difference.

CONCLUSIONS

Delivery at 38-41wg could be beneficial for those with high grade stomach position.

Fetal liver and lung volume index of neonatal survival with congenital diaphragmatic hernia

BACKGROUND

Magnetic resonance imaging (MRI) assesses pulmonary hypoplasia in fetal congenital diaphragmatic hernia (CDH). Neonatal mortality may occur with CDH.

OBJECTIVE

To quantify MRI parameters associated with neonatal survival in fetuses with isolated CDH.

MATERIALS AND METHODS

Fetal MRI for assessing CDH included region of interest (ROI) measurements for total lung volume (TLV), herniated liver volume, herniated other organ volume and predicted lung volume. Ratios of observed lung volume and liver up volume to predicted lung volume (observed to predicted TLV, percentage of the thorax occupied by liver) were calculated and compared to neonatal outcomes. Analyses included Wilcoxon rank sum test, multivariate logistic regression and receiver operating characteristic (ROC) curves.

RESULTS

Of 61 studies, the median observed to predicted TLV was 0.25 in survivors and 0.16 in non-survivors (P=0.001) with CDH. The median percentage of the thorax occupied by liver was 0.02 in survivors and 0.22 in non-survivors (P<0.001). The association of observed to predicted TLV and percentage of the thorax occupied by liver with survival for gestational age (GA) >28 weeks was greater compared to GA ≤28 weeks. The ROC analysis demonstrated an area under the curve of 0.96 (95% confidence interval 0.91-1.00) for the combined observed to predicted TLV, percentage of the thorax occupied by liver and GA.

CONCLUSION

The percentage of the thorax occupied by liver and observed to predicted TLV was predictive of neonatal survival in fetuses with CDH.

Left congenital diaphragmatic hernia and gastroschisis in a term male infant

A term male infant was born to a healthy 24-year-old mother with antenatally diagnosed liver-up, left congenital diaphragmatic hernia (CDH) and gastroschisis. The infant was stabilised in the neonatal intensive care unit and then underwent primary repair of the CDH via left subcostal incision and silo placement for the gastroschisis. Serial silo reductions were started postoperatively and umbilical flap closure for the gastroschisis was performed on day of life 6. The patient was weaned from respiratory support, started on enteral feeds, and discharged home at 1 month of age. He was weaned from supplemental nasogastric feeds by 6 weeks of age and is currently well and thriving at 11 months of age.

Honeymoon Period in Newborn Rats With CDH Is Associated With Changes in the VEGF Signaling Pathway

Background: Patients with congenital diaphragmatic hernia (CDH) have a short postnatal period of ventilatory stability called the honeymoon period, after which changes in pulmonary vascular reactivity result in pulmonary hypertension. However, the mechanisms involved are still unknown. The aim of this study was to evaluate mechanical ventilation's effect in the honeymoon period on VEGF, VEGFR-1/2 and eNOS expression on experimental CDH in rats. Materials and Methods: Neonates whose mothers were not exposed to nitrofen formed the control groups (C) and neonates with left-sided defects formed the CDH groups (CDH). Both were subdivided into non-ventilated and ventilated for 30, 60, and 90 min (n = 7 each). The left lungs (n = 4) were evaluated by immunohistochemistry of the pulmonary vasculature (media wall thickness), VEGF, VEGFR-1/2 and eNOS. Western blotting (n = 3) was performed to quantify the expression of VEGF, VEGFR-1/2 and eNOS. Results: CDH had lower biometric parameters than C. Regarding the pulmonary vasculature, C showed a reduction in media wall thickness with ventilation, while CDH presented reduction with 30 min and an increase with the progression of the ventilatory time (honeymoon period). CDH and C groups showed different patterns of VEGF, VEGFR-1/2 and eNOS expressions. The receptors and eNOS findings were significant by immunohistochemistry but not by western blotting, while VEGF was significant by western blotting but not by immunohistochemistry. Conclusion: VEGF, its receptors and eNOS were altered in CDH after mechanical ventilation. These results suggest that the VEGF-NO pathway plays an important role in the honeymoon period of experimental CDH.

Influence of Gestational Age and Mode of Delivery on Neonatal Outcomes in Prenatally Diagnosed Isolated Congenital Diaphragmatic Hernia

AIM

The optimal gestational age (GA) at delivery and mode of delivery (MoD) for pregnancies with fetal congenital diaphragmatic hernia (CDH) is undetermined. The impact of early term (37-38 weeks 6 days) versus full term (39-40 weeks 6 days) and MoD on immediate neonatal outcomes in prenatally diagnosed isolated CDH cases was evaluated.

MATERIAL AND METHODS

A retrospective chart review of pregnancies evaluated and delivered with the prenatal diagnosis of CDH between July 1, 2008, and December 31, 2018. The primary outcome was survival to hospital discharge. Secondary outcomes included neonatal intensive care unit (NICU) length of stay (LOS), extracorporeal membrane oxygenation (ECMO) requirement and need for supplemental oxygen at day 30 of life.

RESULTS

A total of 296 patients were prenatally evaluated for CDH and delivered in a single center during the study period. After applying exclusion criteria, data were available on 113 women who delivered early term and 72 women who delivered full term. Survival to hospital discharge was comparable between the 2 groups - 83.2% in the early term versus 93.1% in the full term (p = 0.07; 95% CI of 0.13-1.04). No difference was observed in any other secondary outcomes. MoD was stratified into spontaneous vaginal, induced vaginal, unplanned cesarean and scheduled cesarean delivery with associated neonatal survival rates of 74.2, 90.6, 89.7 and 88.2%, respectively, p = 0.13. The 5-min Apgar score was higher in the elective cesarean group (7.94) followed by the induced vaginal delivery group (7.8) compared to 7.17 and 7.18 in the spontaneous vaginal and unplanned cesarean groups, respectively (p = 0.03). The GA and MoD did not influence survival to hospital discharge nor NICU LOS in multivariate analysis.

CONCLUSIONS

Though there were no significant differences in neonatal outcomes for early term compared to full term deliveries of CDH neonates, a trend toward improved survival rates and lower ECMO requirements in the full term group may suggest an underlying importance GA at delivery. Further studies are warranted to validate these findings.

Lung Metabolomics Profiling of Congenital Diaphragmatic Hernia in Fetal Rats

Congenital diaphragmatic hernia (CDH) is characterized by the herniation of abdominal contents into the thoracic cavity during the fetal period. This competition for fetal thoracic space results in lung hypoplasia and vascular maldevelopment that can generate severe pulmonary hypertension (PH). The detailed mechanisms of CDH pathogenesis are yet to be understood. Acknowledgment of the lung metabolism during the in-utero CDH development can help to discern the CDH pathophysiology changes. Timed-pregnant dams received nitrofen or vehicle (olive oil) on E9.5 day of gestation. All fetal lungs exposed to nitrofen or vehicle control were harvested at day E21.5 by C-section and processed for metabolomics analysis using nuclear magnetic resonance (NMR) spectroscopy. The three groups analyzed were nitrofen-CDH (NCDH), nitrofen-control (NC), and vehicle control (VC). A total of 64 metabolites were quantified and subjected to statistical analysis. The multivariate analysis identified forty-four metabolites that were statistically different between the three groups. The highest Variable importance in projection (VIP) score (>2) metabolites were lactate, glutamate, and adenosine 5'-triphosphate (ATP). Fetal CDH lungs have changes related to oxidative stress, nucleotide synthesis, amino acid metabolism, glycerophospholipid metabolism, and glucose metabolism. This work provides new insights into the molecular mechanisms behind the CDH pathophysiology and can explore potential novel treatment targets for CDH patients.

Laparoscopic management of symptomatic congenital diaphragmatic hernia of Morgagni in the adult

BACKGROUND

Currently, there is a relative paucity of literature regarding the management of symptomatic congenital diaphragmatic hernia of the foramen of Morgagni in the adult. This study aims to describe our unique surgical technique and outcomes in adult patients undergoing laparoscopic repair of symptomatic Morgagni hernia.

METHODS

This is a retrospective review of adult patients from 2003 to 2020 who underwent a laparoscopic Morgagni hernia repair at our institution. All patients underwent a similar laparoscopic approach, utilizing the surgical principles of reduction of intra-abdominal contents, complete resection of the hernia sac, followed by primary repair of the hernia defect and mesh reinforcement with permanent mesh if the primary repair was subjectively under tension.

RESULTS

The study population consisted of 12 consecutive patients with a Morgagni hernia. Patients presented with a variety of symptoms attributed to the hernia, including pain 83% (n = 10), respiratory symptoms and shortness of breath 58% (7), and gastrointestinal obstruction 25% (3). Other complaints included: nausea 33% (4), reflux 50% (6), early satiety 8% (1), palpitations 16% (2), a gurgling sensation in the chest 8% (1), and weight loss 8% (1). Primary repair was possible in all patients following complete reduction of hernia contents including the hernia sac. Mesh reinforcement was used in 5 of 12 patients. Average surgical operative time was 93 (± 37) min. Median length of stay was 1.3 days (range 0.5-5.5 days). At a median follow-up of 10.9 months (IQR 8.0-41.5 months), all symptoms attributed to the hernia had resolved. No recurrences were identified.

CONCLUSIONS

Adults with symptomatic Morgagni hernia should undergo surgical repair. A laparoscopic approach utilizing the surgical principles of reduction of intra-abdominal contents, complete resection of the hernia sac, followed by primary repair of the hernia defect (when possible), with or without mesh reinforcement can be performed safely and effectively.

Unraveling the Genetics of Congenital Diaphragmatic Hernia: An Ongoing Challenge

Congenital diaphragmatic hernia (CDH) is a congenital structural anomaly in which the diaphragm has not developed properly. It may occur either as an isolated anomaly or with additional anomalies. It is thought to be a multifactorial disease in which genetic factors could either substantially contribute to or directly result in the developmental defect. Patients with aneuploidies, pathogenic variants or de novo Copy Number Variations (CNVs) impacting specific genes and loci develop CDH typically in the form of a monogenetic syndrome. These patients often have other associated anatomical malformations. In patients without a known monogenetic syndrome, an increased genetic burden of de novo coding variants contributes to disease development. In early years, genetic evaluation was based on karyotyping and SNP-array. Today, genomes are commonly analyzed with next generation sequencing (NGS) based approaches. While more potential pathogenic variants are being detected, analysis of the data presents a bottleneck-largely due to the lack of full appreciation of the functional consequence and/or relevance of the detected variant. The exact heritability of CDH is still unknown. Damaging de novo alterations are associated with the more severe and complex phenotypes and worse clinical outcome. Phenotypic, genetic-and likely mechanistic-variability hampers individual patient diagnosis, short and long-term morbidity prediction and subsequent care strategies. Detailed phenotyping, clinical follow-up at regular intervals and detailed registries are needed to find associations between long-term morbidity, genetic alterations, and clinical parameters. Since CDH is a relatively rare disorder with only a few recurrent changes large cohorts of patients are needed to identify genetic associations. Retrospective whole genome sequencing of historical patient cohorts using will yield valuable data from which today's patients and parents will profit Trio whole genome sequencing has an excellent potential for future re-analysis and data-sharing increasing the chance to provide a genetic diagnosis and predict clinical prognosis. In this review, we explore the pitfalls and challenges in the analysis and interpretation of genetic information, present what is currently known and what still needs further study, and propose strategies to reap the benefits of genetic screening.

ATS Core Curriculum 2020. Pediatric Pulmonary Medicine

The American Thoracic Society Core Curriculum updates clinicians annually in adult and pediatric pulmonary disease, medical critical care, and sleep medicine, in a 3- to 4-year recurring cycle of topics. These topics will be presented at the 2020 International Conference. Below is the pediatric pulmonary medicine core, including pediatric hypoxemic respiratory failure; modalities in noninvasive management of chronic respiratory failure in childhood; surgical and nonsurgical management of congenital lung malformations; an update on smoke inhalation lung injury; an update on vaporizers, e-cigarettes, and other electronic delivery systems; pulmonary complications of sarcoidosis; pulmonary complications of congenital heart disease; and updates on the management of congenital diaphragmatic hernia.

The quantitative lung index: the left lung

OBJECTIVE

We have previously described a gestational age-independent sonographic parameter to assess fetal lung growth in the right lung (right quantitative lung index, or QLI-R). The purpose of this study was to develop a similar sonographic parameter to assess the growth of the left lung in the fetus, independent of gestational age, or QLI-L.

STUDY DESIGN

A new index, the QLI-L was derived using published formulas for the head circumference (HC) and the area of the base of the left lung (LA), with the corresponding percentiles.

RESULTS

Left lung growth can be expressed using the following formula: QLI-L=LAL(HC12)2. The 50th percentile of the QLI-L remained approximately constant at 1.0 for the GA between 16-32 weeks. A small left lung (<1st percentile) was defined as a QLI-L < 0.5.

CONCLUSIONS

Fetal left lung growth can be adequately described independent of gestational age using the QLI-L. Further experience is needed to assess the clinical accuracy of the QLI-L in characterizing fetal left lung growth.

What should we tell parents? Congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is characterized by a defect in the muscle dividing the thoracic and abdominal cavities. This leads to herniation of the abdominal organs into the thorax and a disturbance of lung development. Two-thirds of cases are identified by prenatal ultrasound in the second trimester, which should prompt referral to a tertiary center for prognosis assessment and counseling by a multidisciplinary team familiar with this condition. In this review, we summarize evidence on prenatal diagnosis and postnatal management of CDH. There is a focus on information that should be provided to expecting parents during prenatal counseling.

Prevalence and mortality in children with congenital diaphragmatic hernia: a multicountry study

PURPOSE

This study determined the prevalence, mortality, and time trends of children with congenital diaphragmatic hernia (CDH).

METHODS

Twenty-five hospital- and population-based surveillance programs in 19 International Clearinghouse for Birth Defects Surveillance and Research member countries provided birth defects mortality data between 1974 and 2015. CDH cases included live births, stillbirths, or elective termination of pregnancy for fetal anomalies. Prevalence, cumulative mortality rates, and 95% confidence intervals (CIs) were calculated using Poisson regression and a Kaplan-Meier product-limit method. Joinpoint regression analyses were conducted to assess time trends.

RESULTS

The prevalence of CDH was 2.6 per 10,000 total births (95% CI: 2.5-2.7), slightly increasing between 2001 and 2012 (average annual percent change = 0.5%; 95% CI:-0.6 to 1.6). The total percent mortality of CDH was 37.7%, with hospital-based registries having more deaths among live births than population-based registries (45.1% vs. 33.8%). Mortality rates decreased over time (average annual percent change = -2.4%; 95% CI: -3.8 to 1.1). Most deaths due to CDH occurred among 2- to 6-day-old infants for both registry types (36.3%, hospital-based; 12.1%, population-based).

CONCLUSIONS

The mortality of CDH has decreased over time. Mortality remains high during the first week and varied by registry type.

Prevalence and risk factors for congenital diaphragmatic hernia: A global view

PURPOSE

To determine the global prevalence for congenital diaphragmatic hernia (CDH) and identify CDH-related risk factors.

METHODS

Using a defined strategy, a systematic review of the literature was conducted according to PRISMA guidelines, searching for population-based epidemiological studies to evaluate the prevalence of CDH globally and per country. Studies containing overlapping populations or timeframes were excluded. CDH-related risk factors were calculated by meta-analysis using RevMan5.3 and expressed as risk ratio and 95% confidence interval.

RESULTS

Prevalence: Of 8230 abstracts screened, 30 full-text articles published between 1980 and 2019 were included. The overall prevalence of CDH was 2.3 in 10,000 births (16,710 CDH babies in 73,663,758 livebirths).

RISK FACTORS

From 9 studies we found that male sex [RR 1.38 (1.05-1.80), p=0.02] and maternal age >35 years [RR 1.69 (1.26-2.25), p=0.0004] were associated with CDH. Conversely, maternal black ethnicity resulted as a protective factor [RR 0.82 (0.77-0.89, p<0.00001].

CONCLUSION

This study reveals that there is a worldwide paucity of population-based studies, and those studies that report on prevalence and risk factors come from a small number of countries. The prevalence of CDH varies within and across geographical world regions. The main risk factors for CDH identified are male sex and older maternal age. More epidemiological studies, involving more world regions, are needed to identify possible strategies to help strengthen our understanding of the risk factors, provide clinicians with the tools necessary for prenatal and postnatal counseling, and inform policy makers on how to strategize CDH care in different parts of the world.

TYPE OF STUDY

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level III.

High-frequency vs. conventional ventilation at the time of CDH repair is not associated with higher mortality and oxygen dependency: a retrospective cohort study

PURPOSE

The VICI-trial reported that in patients with congenital diaphragmatic hernia (CDH), mortality or bronchopulmonary dysplasia (BPD) were equivalent using conventional mechanical ventilation (CMV) and high-frequency oscillatory ventilation. The purpose of this study was to determine if the mode of ventilation at the time of CDH repair affected mortality or oxygen dependence at 28 days.

METHODS

We performed a retrospective cohort study of infants born wih CDH from 1991 to 2015. A generalized linear model was applied to the data using a propensity score analysis.

RESULTS

Eighty patients met the inclusion criteria; at the time of surgery 39 (48.8%) patients were on HFV and 41 (51.3%) patients were on CMV. In the HFV group, 16 (47.1%) patients remained oxygen dependent and there were 5 (12.8%) deaths at 28 days. In the CMV group, 5 (12.2%) patients remained oxygen dependent at 28 days but none had died. The base model demonstrated that the HFV group had increased rates of oxygen dependence [OR = 6.40 (2.13, 22.2), p = 0.002]. However, after propensity score analysis, we found no difference between HFV and CMV.

CONCLUSION

Our study suggests that in infants with CDH, there is no significant difference between HFV and CMV in oxygen dependency or death.

Transgenic animal models of congenital diaphragmatic hernia: a comprehensive overview of candidate genes and signaling pathways

Congenital diaphragmatic hernia (CDH) is a relatively common and life-threatening birth defect, characterized by incomplete formation of the diaphragm. Because CDH herniation occurs at the same time as preacinar airway branching, normal lung development becomes severely disrupted, resulting almost invariably in pulmonary hypoplasia. Despite various research efforts over the past decades, the pathogenesis of CDH and associated lung hypoplasia remains poorly understood. With the advent of molecular techniques, transgenic animal models of CDH have generated a large number of candidate genes, thus providing a novel basis for future research and treatment. This review article offers a comprehensive overview of genes and signaling pathways implicated in CDH etiology, whilst also discussing strengths and limitations of transgenic animal models in relation to the human condition.

Discordant prenatal ultrasound and fetal MRI in CDH: wherein lies the truth?

PURPOSE

Prenatal risk assessment of congenital diaphragmatic hernia (CDH) relies on prenatal ultrasound (U/S) and fetal magnetic resonance imaging (MRI). When the modalities differ in prognosis, it is unclear which is more reliable.

METHODS

Retrospective chart review identified cases of prenatally diagnosed CDH from 4/2010-6/2018 meeting inclusion criteria. Demographic, radiologic, and postnatal outcomes data were collected. Ultrasound- versus MRI-based prognosis (mild, moderate, and severe) was compared with clinical outcomes. Kappa measures compared congruency in disease severity scaling between imaging modalities, while logistic regression and receiver operating characteristics curves compared the ability of each modality to predict outcomes.

RESULTS

Forty-two patients met criteria. Both U/S- and MRI-based prognosis categories differentiated for survival. MRI categories differentiated for ECMO use, surgical repair, and defect type. O/e TFLV better discriminated for survivors and defect type than o/e LHR. Seventeen (40.5%) had discordant prenatal prognostic categories. In 13/17 (76.5%), o/e TFLV predicted higher severity when compared to o/e LHR, but sample size was insufficient to compare accuracy in cases of discordance.

CONCLUSIONS

Clinical outcomes suggest fetal MRI may more accurately predict severe pulmonary hypoplasia compared to prenatal ultrasound. Our analysis suggests fetal MRI is a valuable adjunct in the prenatal evaluation of CDH.

LEVEL OF EVIDENCE

Level III.

TYPE OF STUDY

Retrospective Review.

Implications of Atrial-Level Shunting by Echocardiography in Newborns with Congenital Diaphragmatic Hernia

OBJECTIVE

To determine whether postnatal echocardiographic indices of left ventricular (LV) size and function are associated with atrial-level shunt direction and investigate whether a relationship exists between LV function and LV size in patients with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This was a single-center retrospective study of 51 neonates with CDH evaluated at Children's Hospital Colorado. Initial postnatal echocardiograms were analyzed for cardiac dimensions, valvar integrity, cardiac time intervals, and biventricular function. Comparisons were made between neonates with left-to-right vs right-to-left atrial-level shunting, as well as between those with decreased (ejection fraction <55%) vs normal (ejection fraction ≥55%) LV function.

RESULTS

The majority (82.4%) of infants with CDH had a left-to-right atrial-level shunt, and 84.3% had systemic or suprasystemic pulmonary artery pressure. Decreased LV function was demonstrated in 37.2% and was associated with smaller LV volumes and worse outcomes, including the need for extracorporeal membrane oxygenation (ECMO) and survival.

CONCLUSIONS

Left-to-right atrial-level shunting is common in neonates with severe CDH, even in the presence of suprasystemic pulmonary artery pressure. LV dysfunction correlates with decreased LV volumes and is associated with adverse neonatal outcomes, including increased need for ECMO and decreased survival.

Prenatal prediction of postnatal survival in fetuses with congenital diaphragmatic hernia using MRI: lung volume measurement, signal intensity ratio, and effect of experience

Objective: To evaluate various signal intensity ratios in isolated congenital diaphragmatic hernia (CDH) and to compare their potential in predicting survival with that of the observed-to-expected (O/E) ratio of total fetal lung volume (TFLV) using magnetic resonance imaging (MRI) measurements. Our second objective was to evaluate the impact of operator's experience in comparing the prediction of postnatal survival by O/E-TFLV.Methods: In 75 conservatively managed CDH fetuses and in 50 who underwent fetoscopic endoluminal tracheal occlusion (FETO), the fetal lung-to-amniotic fluid, lung-to-liver, lung-to-muscle, lung-to-spinal fluid signal intensity ratios, respectively LAFSIR, LLSIR, LMSIR, and LSFSIR, were measured, as was O/E-TFLV. Receiver operating characteristic (ROC) curves were constructed and used to compare the various signal intensity ratios with O/E-TFLV in the prediction of postnatal survival. In 72 MRI lung volumes assessed by the referring radiologists in Paris and Lille and secondarily by our expert radiologist in Brussels (M.M.C.) using the same MRI examinations, ROC curves were constructed and used to compare the value of O/E-TFLV determined by the two centers in the prediction of postnatal survival.Results: In the total cohort of CDH fetuses, O/E-TFLV and LLSIR were predictive of postnatal survival whereas in the conservatively managed group O/E-TFLV, LLSIR, and LMSIR predicted postnatal survival. O/E-TFLV predicted postnatal survival far better than the signal intensity ratios: area under the ROC curve for prediction by O/E-TFLV in the total cohort was 0.866 (p < .001; standard error = 0.031). The area under the ROC curve for prediction of postnatal survival using O/E-TFLV by MRI evaluated at the referral centers was 0.640 (p = 102; standard error = 0.085), and with O/E-TFLV reevaluated by M.M.C., it was 0.872 (p < .001; standard error = 0.061). Pairwise comparison showed a significant difference between the areas under the ROC curves (difference = 0.187, p = .012; standard error = 0.075).Conclusion: In fetuses with CDH with/without FETO, LLSIR was significantly correlated with the prediction of postnatal survival. However, measurement of O/E-TFLV was far better in predicting postnatal outcome. Operator experience in measurement of lung volumes using MRI seem to play a role in the predictive value of the technique.

Survival trends and outcomes among preterm infants with congenital diaphragmatic hernia

OBJECTIVE

The objective of this study was to use current national data to evaluate the characteristics and survival trends of preterm infants born with CDH from 2004 to 2014.

STUDY DESIGN

Data was queried from the National Inpatient Sample (NIS) and KID database from 2004 to 2014. Infants were included if diagnosed with CDH by ICD-9 coding and gestational age <37 weeks. Descriptive statistics, chi-square, and trend analysis were completed.

RESULTS

We identified 2356 infants born prematurely with CDH. The overall survival rate was 49%. The survival range is 21.2-62.3% for gestational age <26 weeks to 35-36 weeks, respectively. Total mortality was 1183; of them, 1052 (89%) were not repaired and 363 (30.7%) did not receive mechanical ventilation. Surgical repair occurred in 55.1% of infants.

CONCLUSIONS

Preterm infants have lower survival compared with term infants. Survival rates decrease with lower gestational age and have improved over time.

Heterogeneous Response in Rabbit Fetal Diaphragmatic Hernia Lungs After Tracheal Occlusion

BACKGROUND

Fetal tracheal occlusion (TO) is an experimental therapeutic approach to stimulate lung growth in the most severe congenital diaphragmatic hernia (CDH) cases. We have previously demonstrated a heterogeneous response of normal fetal rabbit lungs after TO with the appearance of at least two distinct zones. The aim of this study was to examine the fetal lung response after TO in a left CDH fetal rabbit model.

METHODS

Fetal rabbits at 25 d gestation underwent surgical creation of CDH followed by TO at 27 d and harvest on day 30. Morphometric analysis, global metabolomics, and fluorescence lifetime imaging microscopy (FLIM) were performed to evaluate structural and metabolic changes in control, CDH, and CDH + TO lungs.

RESULTS

Right and left lungs were different at the baseline and had a heterogeneous pulmonary growth response in CDH and after TO. The relative percent growth of the right lungs in CDH + TO was higher than the left lungs. Morphometric analyses revealed heterogeneous tissue-to-airspace ratios, in addition to size and number of airspaces within and between the lungs in the different groups. Global metabolomics demonstrated a slower rate of metabolism in the CDH group with the left lungs being less metabolically active. TO stimulated metabolic activity in both lungs to different degrees. FLIM analysis demonstrated local heterogeneity in glycolysis, oxidative phosphorylation (OXPHOS), and FLIM "lipid-surfactant" signal within and between the right and left lungs in all groups.

CONCLUSIONS

We demonstrate that TO leads to a heterogeneous morphologic and metabolic response within and between the right and left lungs in a left CDH rabbit model.

Accuracy of estimated fetal weight assessment in fetuses with congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia is a congenital anomaly in which fetal abdominal organs herniate into the thoracic cavity through a diaphragmatic defect, which can impede fetal lung development. Standard formulas for estimated fetal weight include measurement of fetal abdominal circumference, which may be inaccurate in fetuses with congenital diaphragmatic hernia because of displacement of abdominal contents into the thorax.

OBJECTIVES

This study aimed to assess the accuracy of standard estimated fetal weight assessment in fetuses with congenital diaphragmatic hernia by comparing prenatal assessment of fetal weight with actual birthweight.

STUDY DESIGN

A retrospective cohort study of fetuses diagnosed with congenital diaphragmatic hernia was performed at a single center from 2012 to 2018. Fetuses with multiple anomalies or confirmed chromosome abnormalities were excluded. Estimated fetal weight was calculated using the Hadlock formula. Published estimates of fetal growth rate were used to establish a projected estimated fetal weight at birth from the final growth ultrasound, and the percentage difference between projected estimated fetal weight at birth and actual birthweight was calculated. A Wilcoxan rank-sum test was used to examine the difference between projected estimated fetal weight and birthweight.

RESULTS

We had complete data for 77 fetuses with congenital diaphragmatic hernia. The majority (76.6%, 55 of 77) had left-sided congenital diaphragmatic hernia. The median [interquartile range] projected estimated fetal weight was similar to median birthweight, at 3177 g [2691-3568] and 3180 g [2630-3500], respectively, which did not represent a statistically significant difference between projected estimated fetal weight and birthweight (P = .66). The median absolute percentage difference between projected birthweight and actual birthweight was 6.3% [3.2-7.0]. Estimated fetal weight was overall underestimated in a minority of cases (44.2%, 34 of 77).

CONCLUSION

In fetuses with a congenital diaphragmatic hernia, standard measurements of fetal estimated fetal weight show accuracy that is at least comparable with previously established margins of error for ultrasound assessment of fetal weight. Standard estimated fetal weight assessment remains an appropriate method of estimating fetal weight in fetuses with congenital diaphragmatic hernia.

Maternal dietary intake of vitamin A during pregnancy was inversely associated with congenital diaphragmatic hernia: the Japan Environment and Children's Study

The pathogenesis of congenital diaphragmatic hernia (CDH) is largely unknown; however, vitamin A seems to play a role in diaphragmatic development. Previous case-control studies reported that maternal dietary vitamin A intake was inversely associated with the risk of CDH. To our knowledge, however, there is no prospective evidence regarding this association. Our aim was to examine whether maternal intake of vitamin A was associated with CDH occurrence. Baseline data, from the Japan nationwide birth cohort study (2011-2014) of 89 658 mothers (mean age at delivery = 31·2 years) who delivered singleton live births, were analysed. We assessed dietary habits using an FFQ focused on the first trimester and estimated the daily intake of total vitamin A (retinol activity equivalents), retinol, provitamin A carotenoids and vegetables. The occurrence of CDH was ascertained from medical records. A total of forty cases of CDH were documented. The adjusted OR of CDH occurrence for the high total vitamin A intake category (median = 468 μg/d) was 0·6 (95 % CI 0·3, 1·2) with reference to the low intake category (230 μg/d). When we restricted to mothers with a prepregnancy BMI of 18·5-24·9 kg/m2, vitamin A intake was inversely associated with the risk of their children being born with CDH (OR 0·5, 95 % CI 0·2, 1·0). Even given the limited number of cases in the study, our findings provide additional evidence to link vitamin A with CDH.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Lactation Experience of Mothers and Feeding Outcomes of Infants with Congenital Diaphragmatic Hernia

Objective: This study explores the congenital diaphragmatic hernia (CDH) infant-mother dyad with regard to maternal lactation outcomes and infant exposure to a human milk diet. Study Design: This was a retrospective descriptive cohort study conducted at Children's Hospital of Philadelphia. A total of 149 infants born with CDH and admitted to the Newborn/Infant Intensive Care Unit (N/IICU) were included in the study. Results: Of 149 mothers, 141 (95%) initiated pumping for their CDH infants. At discharge from the N/IICU, 79% (n = 118) of infants were being fed human milk. Among those discharged on human milk, 55% (n = 65) were discharged being fed unfortified human milk with 9% (n = 11) being fed unfortified maternal hind milk. Conclusion: This research demonstrates that mothers of CDH infants can effectively establish and maintain a complete milk supply and that the majority of infants with CDH can receive a human milk diet for the entire hospital stay.

Prenatal prediction of survival in congenital diaphragmatic hernia: An audit of postnatal outcomes

PURPOSE

Effective antenatal counseling in congenital diaphragmatic hernia (CDH) relies on proper measurement of prognostic indices. This quality initiative audited the accuracy of prenatal imaging with postnatal outcomes at two tertiary pediatric referral centers.

METHODS

Prenatal lung-head ratio (LHR) and total fetal lung volume (TFLV) for CDH patients treated between 2006 and 2017 were retrieved. Study inclusion required at least one LHR or TFLV measurement between 24 and 32 weeks gestational age. Postnatal outcomes [mortality, extracorporeal life support (ECLS) need, patch repair, persistent pulmonary hypertension, oxygen requirement at 28 days] were abstracted from the Canadian Pediatric Surgery Network (CAPSNet) database and local chart review. Univariate and descriptive analyses were conducted.

RESULTS

Eighty-two of 121 eligible CDH patients (68%) were included. Overall mortality, ECLS rates, and patch repair were 33%, 12.5%, and 45%, respectively. Lower LHR values correlated with increased rates of each outcome and persisted despite multiple measurements. Values obtained were higher than those in published schemata. LHR values >45% were most associated with survival, avoidance of ECLS, and primary repair. TFLV values only correlated with mortality and patch repair.

CONCLUSIONS

This audit confirms that LHR and TFLV values predict CDH outcomes. However, absolute values obtained require careful interpretation and internal review.

LEVEL OF EVIDENCE

IV.