A population-based study of congenital diaphragmatic hernia

Patent ductus arteriosus shunting direction and diameter predict inpatient outcomes in newborns with congenital diaphragmatic hernia

Objective

To evaluate whether the patent ductus arteriosus (PDA) can serve as a predictive factor for inpatient outcomes in congenital diaphragmatic hernia (CDH) patients.

Methods

A retrospective cohort study was conducted on 59 CDH patients at the Capital Institute of Pediatrics from January 2020 to August 2022. Echocardiography was performed at least three times: within 2-3 h after birth, pre-operatively, and post-operatively of CDH surgery. Based on the direction of the PDA shunt in the first echocardiogram, patients were classified into three groups: left-to-right shunting or closed PDA (L-R), bi-directional shunting, and right-to-left shunting (R-L).

Results

The mortality rate was 15.3% (9/59), with all non-survivors having R-L shunting and group mortality of 39.1% (9/23). The direction of the PDA shunt was significantly associated with the duration of ventilation and length of hospital stay (p < 0.05). Decreased PDA diameter or pre-operative shunting direction change towards L-R or bi-directional shunting were associated with higher survival rates, while increased PDA diameter or continuous R-L shunting were associated with higher mortality rates. Pre-operative PDA shunt direction, PDA size after birth and before surgery, gestational age of diagnosis, and shortening fraction before surgery were significantly correlated with patient outcomes. The direction of the preoperative PDA shunt was the most relevant factor among these relationships (p = 0.009, OR 20.6, CI 2.2∼196.1).

Conclusion

Our findings highlight the importance of monitoring changes in PDA shunt directionality and diameter in the early stage after birth, as these parameters may serve as valuable predictors of patient outcomes.

Seasonal Variation of Congenital Diaphragmatic Hernia: A Review of the Literature and Database Report from the United States and Canada

INTRODUCTION

 The etiology of congenital diaphragmatic hernia (CDH) remains unknown and only 10 to 30% of patients have a genetic cause. Seasonal variation is known to contribute to the development of some congenital anomalies. Our aim was to investigate whether CDH births have seasonal variation.

MATERIALS AND METHODS

 A literature review was conducted for CDH and seasonality. Moreover, data from the CDH International Patient Registry Database were collected for infants with due dates between 2008 and 2014. Due dates were used to determine seasonal distribution of births. Birth rates per month in the United States and Canada were extracted from publicly available databases. Data were analyzed using analysis of variance and contingency tables.

RESULTS

 First, the literature review revealed 11 articles, of which 3 were eligible for inclusion. These studies reported conflicting results on seasonality of CDH. Second, we extracted due dates from the CDH International Patient Registry Database (1,259 patients) and found that there were fewer due dates in winter months (12.1 ± 4 patients/month) than in summer (16.7 ± 6 patients/month; p = 0.011) and fall months (16.3 ± 5 patients/month; p = 0.022). Although this trend was similar to that of all births in the United States and Canada, a lower incidence was observed in winter for CDH infants (20.2%) than for the general population (24.1%, p = 0.0012). CDH survival rate did not vary by season.

CONCLUSION

 This study provides evidence for a seasonal variation of CDH births. No causative link was established between CDH development and seasonality. Population-based studies with a focus on exposome data are needed to explain seasonal variation in CDH.

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.

Fibroblast-derived Hgf controls recruitment and expansion of muscle during morphogenesis of the mammalian diaphragm

The diaphragm is a domed muscle between the thorax and abdomen essential for breathing in mammals. Diaphragm development requires the coordinated development of muscle, connective tissue, and nerve, which are derived from different embryonic sources. Defects in diaphragm development cause the common and often lethal birth defect, congenital diaphragmatic hernias (CDH). HGF/MET signaling is required for diaphragm muscularization, but the source of HGF and the specific functions of this pathway in muscle progenitors and effects on phrenic nerve have not been explicitly tested. Using conditional mutagenesis in mice and pharmacological inhibition of MET, we demonstrate that the pleuroperitoneal folds (PPFs), transient embryonic structures that give rise to the connective tissue in the diaphragm, are the source of HGF critical for diaphragm muscularization. PPF-derived HGF is directly required for recruitment of MET+ muscle progenitors to the diaphragm and indirectly (via its effect on muscle development) required for phrenic nerve primary branching. In addition, HGF is continuously required for maintenance and motility of the pool of progenitors to enable full muscularization. Localization of HGF at the diaphragm's leading edges directs dorsal and ventral expansion of muscle and regulates its overall size and shape. Surprisingly, large muscleless regions in HGF and Met mutants do not lead to hernias. While these regions are likely more susceptible to CDH, muscle loss is not sufficient to cause CDH.

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.

Synthetic versus Biological Patches for CDH: A Comparison of Recurrence Rates and Adverse Events, Systematic Review, and Meta-Analysis

OBJECTIVE

 Our systematic review aims to compare recurrence rates and complications of biological versus synthetic patches for the repair of congenital diaphragmatic herniae.

METHODS

 Studies from January 1, 1980 to April 25, 2020, with patients under the age of 16 years and with a minimum 6-month follow-up, were included from MEDLINE, Embase, and Cochrane databases. Funnel plots for recurrence rates were constructed for biological and synthetic patches. Subgroup analysis was performed for recurrence rate at the 1-year time-point and data were gathered on individual adverse events from relevant studies.

RESULTS

 A total of 47 studies with 986 patients (226 biological, 760 synthetic) were included. Funnel plot analysis determined overall recurrence rates of 16.7% for synthetic and 30.3% for biological patches. Subgroup analysis of 493 and 146 patients with synthetic and biological patches, respectively, showed recurrence rates of 9.9 and 26%, respectively.The most commonly used patch types-PTFE (polytetrafluoroethylene) and SIS (small intestinal submucosa)-had 11.5 and 33.3% recurrence, respectively. Adhesive bowel obstruction rates ranged from 4 to 29% in studies that systematically reported it for synthetic, and 7 to 35% for biological patches. Gastroesophageal reflux rates ranged from 25 to 48% in studies that systematically reported it for synthetic, and 21 to 42% for biological patches. Pectus deformity rates were reported as high as 80% for synthetic patches.

CONCLUSION

 Biological patches appear to have higher recurrence rates than synthetic patches, while skeletal deformities are associated more commonly with synthetic patches. Results of biological patches are mainly using SIS and this may overestimate complications of current superior biological patches.

TITF1 Screening in Human Congenital Diaphragmatic Hernia (CDH)

TITF1 (Thyroid Transcription Factor-1) is a homeodomain-containing transcription factor. Previous studies showed that Titf1 null mice are characterized by failure of tracheo-oesophageal separation and impaired lung morphogenesis resulting in Pulmonary Hypoplasia (PH). In this study, we aim to evaluate the role of TITF1 in the pathogenesis of congenital diaphragmatic hernia (CDH) in humans. We investigated TITF1 expression in human trachea and lungs and performed direct mutation analysis in a CDH population. We studied 13 human fetuses at 14 to 24 weeks of gestation. Five μm sections were fixed in paraformaldehyde and incubated with anti-TITF1 primary antibody. Positive staining was visualized by biotinylated secondary antibody. We also performed TITF1 screening on genomic DNA extracted from peripheral blood of 16 patients affected by CDH and different degrees of PH, searching for mutations, insertions, and/or deletions, by sequencing the exonic regions of the gene. Histochemical studies showed positive brown staining of fetal follicular thyroid epithelium, normal fetal trachea, and normal fetal lung bronchial epithelium. Fetal esophageal wall was immunohistochemically negative. Molecular genetic analysis showed complete identity between the sequences obtained and the Wild Type (WT) form of the gene in all cases. No mutation, insertion and/or deletion was detected. Although TITF1 is expressed in the human fetal lung and has been considered to have a role in the pathogenesis of PH in CDH, the results of our study do not support the hypothesis that TITF1 mutations play a key role in the etiopathogenesis of CDH.

Early Abnormalities in Gas Exchange in Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

To determine how blood gas exchange is altered during the transition in the first hour of life in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This was a prospective observational cohort study evaluating arterial blood gas (ABG) samples and ventilator support in 34 infants with CDH in the first hour of life. Infants were stratified into mild, moderate, and severe CDH. The first ABG was compared with the umbilical cord ABGs and response to intervention evaluated on subsequent ABGs among infants with different CDH severities.

RESULTS

Infants were intubated at a median of 120 seconds (range 50-240 seconds) and ABGs obtained at a median of 6 minutes (IQR 4, 8 minutes), 16 minutes (IQR 13.5, 22.5 minutes), and 60 minutes (IQR 56, 64 minutes). Compared with the cord ABG, first ABG mean partial pressure of carbon dioxide (PaCO₂) increased from 49.8 mm Hg to 82.1 mm Hg, mean base deficit decreased from -2.2 to -7.3, and mean pH from 7.298 to 7.060. With ventilator adjustments, second mean PaCO₂ decreased to 76.7 mm Hg and third mean PaCO₂ 48.5 mm Hg. When stratified, with all CDH severities PaCO₂ increased abruptly, remained elevated in moderate and severe CDH, and improved in all severities by 60 minutes after delivery.

CONCLUSIONS

Gas exchange is markedly altered in the first hour of life in infants with CDH with abrupt onset of acidemia and a mixed respiratory and metabolic acidosis. Early implementation of adequate cardiopulmonary support may contribute to more timely stabilization of gas exchange.

Late presentation of congenital type IV esophageal hiatus hernia in a 9-year-old boy: a case report

Background

Congenital diaphragmatic hernia affects 1 in every 2000–5000 live births. The mediastinum shifts to the opposite side, the lungs are hypoplastic, and the arterioles are abnormal, resulting in pulmonary hypertension. Respiratory and cardiovascular functions are severely impaired at birth, resulting in significant mortality and morbidity as a result of the associated malformations.

Case presentation

A 9-year-old persian boy was referred with complaint of intermittent abdominal pain in the left lower quadrant and an episode of vomiting. The patient was tachypneic, and the abdomen was nontender on examination. Lung sounds on the left side were considerably decreased, whereas heart sounds on the right side were louder. There was no history of underlying disease in the patient. Initial laboratory blood tests, chest x-ray, spiral computed tomography scan, and chest sonography were requested. Blood tests were normal, and chest x-ray revealed a round-shaped lesion with relatively clear boundaries containing air–fluid level and shift of the heart and mediastinum to the right. A spiral computed tomography scan of the lungs demonstrated the shift of the heart and mediastinum to the right side was due to dilated stomach and colon pressure, and chest sonography revealed that half of the stomach was inside the thorax. Laparotomy surgery was performed. The patient had no complications following surgery.

Conclusions

Herniation of abdominal contents through the diaphragmatic hiatus should be suspected in patients with tachypnea and mediastinal shift to the right side. Rapid diagnosis and early surgical treatment are necessary to avert any potentially life-threatening complications.

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.

Maternal Bochdalek Hernia during Pregnancy: A Systematic Review of Case Reports

Background: Since the first report of a diaphragmatic hernia from Ambroise Paré’s necropsy in 1610, the Bochdalek hernia (BH) of the congenital diaphragmatic hernia (CDH) has been the most common types with high morbidity and mortality in the neonatal period. Due to the nature of the disease, CDH associated with pregnancy is too infrequent to warrant reporting in the literature. Mortality of obstruction or strangulation is mostly due to failure to diagnose symptoms early. Data sources and study selection: A systematic literature search of maternal BH during pregnancy was conducted using the electronic databases (PubMed and EMBASE) from January 1941 to December 2020. Because of the rarity of the disease, this review included all primary studies, including case reports or case series that reported at least one case of maternal BH in pregnant. Searches, paper selection, and data extraction were conducted in duplicate. The analysis was performed narratively regardless of the control groups’ presence due to their rarity. Results: The search retrieved 3450 papers, 94 of which were deemed eligible and led to a total of 43 cases. Results of treatment showed 16 cases in delayed delivery after hernia surgery, 10 cases in simultaneous delivery with hernia surgery, 3 cases in non-surgical treatment, and 14 cases in hernia surgery after delivery. Of 16 cases with delayed delivery after hernia surgery, 13 (81%) cases had emergency surgery and three (19%) cases had surgery after expectant management. Meanwhile, 10 cases underwent simultaneous delivery with hernia surgery, 6 cases (60%) had emergent surgery, and 4 cases (40%) had delayed hernia surgery after expectant management. 3 cases underwent non-surgical treatment. In this review, the maternal death rate and fetal/neonatal loss rate from maternal BH was 5% (2/43) and 16% (7/43), respectively. The preterm birth rate has been reported in 35% (15/43) of maternal BH, resulting from maternal deaths in 13% (2/15) of cases and 6 fetal loss in 40% (6/15) of cases; 44% (19/43) of cases demonstrated signs of bowel obstruction, ischemia, or perforation of strangulated viscera in the operative field, resulting from maternal deaths in 11% (2/19) of cases and fetal-neonatal loss in 21% (4/19) of cases. Conclusion: Early diagnosis and surgical intervention are imperative, as a gangrenous or non-viable bowel resection significantly increases mortality. Therefore, multidisciplinary care should be required in maternal BH during pregnancies that undergo surgically repair, and individualized care allow for optimal results for the mother and fetus.

Right-sided strangulating diaphragmatic hernia in an adult without history of trauma: a case report

Background

Diaphragmatic hernia involves protrusion of abdominal contents into the thorax through a defect in the diaphragm. This defect can be caused either by developmental failure of the posterolateral foramina to fuse properly, or by traumatic injury of the diaphragm. Left-sided diaphragmatic hernias are more common (80–90%) because the right pleuroperitoneal canal closes earlier and the liver protects the right diaphragm. Diaphragmatic hernias in adults are relatively asymptomatic, but in some cases may lead to incarcerated bowel, intraabdominal organ dysfunction, or severe pulmonary disease. The aim of this report is to enlighten clinical doctors about this rare entity that can have fatal consequences for the patient.

Case presentation

We present a rare case of a right-sided strangulating diaphragmatic hernia in an adult Caucasian patient without history of trauma. Clinical examination revealed bowel sounds in the right hemithorax, which were confirmed by the presence of loops of small intestine into the right part of the thorax through the right diaphragm, as was shown on chest X-ray and computerized tomography. Deterioration of the clinical status of the patient led to an operation, which revealed strangulated necrotic small bowel. Approximately 1 m of bowel was removed, and laterolateral anastomosis was performed. The patient had an uneventful postoperative recovery and was discharged 8 days later.

Conclusions

Surgery is required to replace emerged organs into the abdomen and to repair diaphragmatic lesion. A delayed approach can have catastrophic complications for a patient.

Isolated congenital diaphragm hernia associated with homozygous SLIT3 gene variant in dizygous twins

Congenital diaphragmatic hernia (CDH) is a serious life-threatening birth defect characterized by abnormal development in the muscular or tendinous portion of the diaphragm during embryogenesis. Despite its high incidence, the etiology of CDH hasn't been fully understood. Genetic factors are important in pathogenesis; however, few single genes have been definitively implicated in human CDH. SLIT1, SLIT2, and SLIT3 (slit guidance ligand) are three human homologs of the drosophila Slit gene. They interact with roundabout (Robo) homolog receptors to affect cell migration, adhesion, cell motility, and angiogenesis and play important roles in cell signaling pathways including the guidance of axons. In this report, we presented dizygous twin babies with CDH related to the SLIT3 gene variant. Previous studies showed that Slit3 null mice had congenital diaphragmatic hernias on or near the ventral midline portion of the central tendon. This is the first report of homozygous SLIT3 variant associated with CDH in humans.

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

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

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.

Congenital diaphragmatic hernia-does the presence of a hernia sac improve outcome? A systematic review of published studies

Early reports have suggested survival benefits associated with a hernia sac in congenital diaphragmatic hernia (CDH). However, these studies have included only small subsets of patients. This systematic review aimed to evaluate differences in outcomes of CDH newborns with and without a hernia sac. PubMed and Embase databases were searched using relevant key terms. Papers were independently reviewed by two authors with final selection approved by the senior author. Original search retrieved 537 papers; the final review included 8 studies (n = 837 patients). There were 168 CDH patients (20%) with a hernia sac with an overall survival of 93% vs 73% for CDH newborns without a sac (p < 0.001). Twenty-three percent of patients with a CDH sac required diaphragm patch repair vs 44% patients without a sac (p < 0.001). Pulmonary hypertension was manifested in 44% of CDH babies with a hernia sac vs 64% without a sac (p < 0.001). Three studies compared ECMO requirement: 15% with a hernia sac and 34% without sac, p < 0.001.Conclusion: This study shows significant survival benefits in newborns associated with presence of a CDH sac. This may be likely related to these infants having more favourable physiology with less severe pulmonary hypertension and/or smaller anatomical defects requiring primary closure only. What is Known: • Early reports have suggested survival benefits associated with a hernia sac in CDH. • Previous studies have included only a small number of patients. What is New: • A systematic review of published studies clearly shows that CDH newborns with a hernia sac have better overall survival outcomes and less severe pulmonary hypertension. • ECMO utilization and patch repair were also less often required in newborns with a hernia sac.

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.

Deep whole-genome sequencing of multiple proband tissues and parental blood reveals the complex genetic etiology of congenital diaphragmatic hernias

The diaphragm is critical for respiration and separation of the thoracic and abdominal cavities, and defects in diaphragm development are the cause of congenital diaphragmatic hernias (CDH), a common and often lethal birth defect. The genetic etiology of CDH is complex. Single-nucleotide variants (SNVs), insertions/deletions (indels), and structural variants (SVs) in more than 150 genes have been associated with CDH, although few genes are recurrently mutated in multiple individuals and mutated genes are incompletely penetrant. This suggests that multiple genetic variants in combination, other not-yet-investigated classes of variants, and/or nongenetic factors contribute to CDH etiology. However, no studies have comprehensively investigated in affected individuals the contribution of all possible classes of variants throughout the genome to CDH etiology. In our study, we used a unique cohort of four individuals with isolated CDH with samples from blood, skin, and diaphragm connective tissue and parental blood and deep whole-genome sequencing to assess germline and somatic de novo and inherited SNVs, indels, and SVs. In each individual we found a different mutational landscape that included germline de novo and inherited SNVs and indels in multiple genes. We also found in two individuals a 343 bp deletion interrupting an annotated enhancer of the CDH-associated gene GATA4, and we hypothesize that this common SV (found in 1%-2% of the population) acts as a sensitizing allele for CDH. Overall, our comprehensive reconstruction of the genetic architecture of four CDH individuals demonstrates that the etiology of CDH is heterogeneous and multifactorial.

Laparoscopic Repair of Bilateral Congenital Diaphragmatic Hernia Without Pulmonary Hypoplasia

We report the case of a 14-month-old female who had a right-sided congenital diaphragmatic hernia (CDH) without pulmonary hypoplasia. The patient was preoperatively diagnosed with a Morgagni hernia due to the size and location of the hernia seen on imaging. However, the patient was found to have bilateral diaphragmatic defects intraoperatively, and her right diaphragm was almost completely absent. Our patient did not have pulmonary hypoplasia or any of the respiratory comorbidities that CDH patients typically present with, though she did have repeated respiratory infections and cough. This case demonstrates that CDH is not always diagnosed in an accurate or timely manner radiographically and that the surgeon should be prepared to potentially repair more of the diaphragm than expected. Additionally, there is a need to study the pathophysiology and genetics of CDHs further.

Prenatal regenerative fetoscopic interventions for congenital anomalies

Fetal intervention has progressed in the past two decades from experimental proof-of-concept to practice-adopted, life saving interventions in human fetuses with congenital anomalies. This progress is informed by advances in innovative research, prenatal diagnosis, and fetal surgical techniques. Invasive open hysterotomy, associated with notable maternal-fetal risks, is steadily replaced by less invasive fetoscopic alternatives. A better understanding of the natural history and pathophysiology of congenital diseases has advanced the prenatal regenerative paradigm. By altering the natural course of disease through regrowth or redevelopment of malformed fetal organs, prenatal regenerative medicine has transformed maternal-fetal care. This review discusses the uses of regenerative medicine in the prenatal diagnosis and management of three congenital diseases: congenital diaphragmatic hernia, lower urinary tract obstruction, and spina bifida.

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.

Retinoic Acid Signaling and Development of the Respiratory System

Retinoic acid (RA), the bioactive metabolite of vitamin A (VA), has long been recognized as a critical regulator of the development of the respiratory system. During embryogenesis, RA signaling is involved in the development of the trachea, airways, lung, and diaphragm. During postnatal life, RA continues to impact respiratory health. Disruption of RA activity during embryonic development produces dramatic phenotypes in animal models and human diseases, including tracheoesophageal fistula, tracheomalacia, congenital diaphragmatic hernia (CDH), and lung agenesis or hypoplasia. Several experimental methods have been used to target RA pathways during the formation of the embryonic lung. These have been performed in different animal models using gain- and loss-of-function strategies and dietary, pharmacologic, and genetic approaches that deplete retinoid stores or disrupt retinoid signaling. Experiments utilizing these methods have led to a deeper understanding of RA's role as an important signaling molecule that influences all stages of lung development. Current research is uncovering RA cross talk interactions with other embryonic signaling factors, such as fibroblast growth factors, WNT, and transforming growth factor-beta.

Asymptomatic congenital intrapericardial diaphragmatic hernia in a woman becoming symptomatic after childbirth

This paper describes a rare case presentation of congenital asymptomatic intrapericardial diaphragmatic hernia. In this case, the female patient survived without symptoms for over 30 years until becoming symptomatic at childbirth. Diaphragmatic hernia occurs when abdominal viscera protrude into the thoracic cavity, with pericardial hernias being the rarest type. Diaphragmatic hernia can be caused by trauma that raises the intra-abdominal pressure, whereas congenital hernias are often symptomatic at birth. It is rare to have a congenital asymptomatic intrapericardial diaphragmatic hernia, where the patient survives until adulthood and subsequently becomes symptomatic after delivering a child; hence, that is the uniqueness of this case.

Minimally Invasive Repair of Pediatric Morgagni Hernias Using Transfascial Sutures with Extracorporeal Knot Tying

BACKGROUND

Morgagni hernias are rare, with a reported incidence of 2% to 5% of congenital diaphragmatic hernias.

OBJECTIVES

To review a laparoscopic technique to repair Morgagni hernias in pediatric patients.

METHODS

Retrospective chart review of pediatric patients who underwent minimally invasive repair of a Morgagni hernia from November 2009 to September 2017 within a defined population.

RESULTS

During an 8-year period, 15 patients with Morgagni hernias were identified. Four patients with Morgagni hernias were excluded because they had open repairs. Eleven Morgagni hernias were repaired through a completely minimally invasive approach. Three repairs were completed using a soft-tissue patch (Gore-Tex patch, W L Gore & Associates Inc, Flagstaff, AZ). All minimally invasive repairs were completed with transfascial sutures using an endoscopic suturing device (Endo Close, Covidien/Medtronic, Fridley, MN) and 2-0 nonabsorbable synthetic sutures with extracorporeal knot tying. Median follow-up was 40 months (range = 2.6 months to 7.3 years). No patients had postoperative pectus excavatum defects. There were no recurrences.

CONCLUSION

Morgagni hernias are amenable to minimally invasive repair with this simple technique. With large defects, synthetic patches should be used. Recurrences are rare, and morbidity is low.

Congenital heart disease associated with congenital diaphragmatic hernia: A systematic review on incidence, prenatal diagnosis, management, and outcome

PURPOSE

The purpose of this study was to evaluate the impact of congenital heart disease (CHD) on infants with congenital diaphragmatic hernia (CDH).

METHODS

Using a defined search strategy (PubMed, Cochrane, Embase, Web of Science MeSH headings), we searched studies reporting the incidence, management, and outcome of CDH infants born with associated CHD.

RESULTS

Of 6410 abstracts, 117 met criteria. Overall, out of 28,974 babies with CDH, 4427 (15%) had CHD, of which 42% were critical. CDH repair was performed in a lower proportion of infants with CHD (72%) than in those without (85%; p < 0.0001). Compared to CDH babies without CHD, those born with a cardiac lesion were more likely to have a patch repair (45% vs. 30%; p < 0.01) and less likely to undergo minimally invasive surgery (5% vs. 17%; p < 0.0001). CDH babies with CHD had a lower survival rate than those without CHD (52 vs. 73%; p < 0.001). Survival was even lower (32%) in babies with critical CHD.

CONCLUSION

CHD has a strong impact on the management and outcome of infants with CDH. The combination of CDH and CHD results in lower survival than those without CHD or an isolated cardiac defect. Further studies are needed to address some specific aspects of the management of this fragile CDH cohort.

TYPE OF STUDY

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level III.

Allogenic tissue-specific decellularized scaffolds promote long-term muscle innervation and functional recovery in a surgical diaphragmatic hernia model

Congenital diaphragmatic hernia (CDH) is a neonatal defect in which the diaphragm muscle does not develop properly, thereby raising abdominal organs into the thoracic cavity and impeding lung development and function. Large diaphragmatic defects require correction with prosthetic patches to close the malformation. This treatment leads to a consequent generation of unwelcomed mechanical stress in the repaired diaphragm and hernia recurrences, thereby resulting in high morbidity and significant mortality rates. We proposed a specific diaphragm-derived extracellular matrix (ECM) as a scaffold for the treatment of CDH. To address this strategy, we developed a new surgical CDH mouse model to test the ability of our tissue-specific patch to regenerate damaged diaphragms. Implantation of decellularized diaphragmatic ECM-derived patches demonstrated absence of rejection or hernia recurrence, in contrast to the performance of a commercially available synthetic material. Diaphragm-derived ECM was able to promote the generation of new blood vessels, boost long-term muscle regeneration, and recover host diaphragmatic function. In addition, using a GFP + Schwann cell mouse model, we identified re-innervation of implanted patches. These results demonstrated for the first time that implantation of a tissue-specific biologic scaffold is able to promote a regenerating diaphragm muscle and overcome issues commonly related to the standard use of prosthetic materials. STATEMENT OF SIGNIFICANCE: Large diaphragmatic hernia in paediatric patients require application of artificial patches to close the congenital defect. The use of a muscle-specific decellularized scaffold in substitution of currently used synthetic materials allows new blood vessel growth and nerve regeneration inside the patch, supporting new muscle tissue formation. Furthermore, the presence of a tissue-specific scaffold guaranteed long-term muscle regeneration, improving diaphragm performance to almost complete functional recovery. We believe that diaphragm-derived scaffold will be key player in future pre-clinical studies on large animal models.

Evaluation and Monitoring of Pulmonary Hypertension in Neonates With Congenital Diaphragmatic Hernia

PURPOSE OF REVIEW

This review aims to describe the assessment of pulmonary hypertension and ventricular function in neonates with congenital diaphragmatic hernia and the long-term follow-up of their pulmonary vascular disease.

RECENT FINDINGS

In 2015, the pediatric pulmonary hypertension guidelines from the American Heart Association and American Thoracic Society suggested class I level of evidence B guidelines for routine evaluation of patients with congenital diaphragmatic hernia, including longitudinal care in an interdisciplinary pulmonary hypertension program and following the recommendations offered for all children with pulmonary hypertension. Congenital diaphragmatic hernia causes compression of the lungs during critical stages of fetal development and results in lung hypoplasia. As a result, there is abnormal development of pulmonary vasculature that leads to post-natal pulmonary hypertension and increased afterload to the right ventricle. Left ventricular filling is affected by decreased pre-load and mechanical compression by abdominal content leading to decreased systemic perfusion. Persistent pulmonary hypertension after surgical repair of congenital diaphragmatic hernia is associated with increased mortality. Assessment and monitoring of pulmonary hypertension and ventricular function in this population of neonates is crucial to determine response to medical treatment, the need for extracorporeal membrane oxygenation, and the timing of surgical repair.

Gene ontology enrichment analysis of congenital diaphragmatic hernia-associated genes

Congenital diaphragmatic hernia (CDH) is a commonly occurring major congenital anomaly with a profound impact on neonatal mortality. The etiology of CDH is poorly understood and is complicated by multiple clinical presentations, reflecting the location and type of diaphragm defect. With the increased power of genetic screening, more genes are being associated with CDH, creating a knowledge gap between CDH-associated genes and their contribution to diaphragm embryogenesis. Our goal was to investigate CDH-associated genes and identify common pathways that may lead to abnormal diaphragm development. A comprehensive list of CDH-associated genes was identified from the literature and categorized according to multiple factors, including type of CDH. We undertook a large-scale gene function analysis using gene ontology to identify significantly enriched biological pathways and molecular functions associated with our gene set. We identified 218 CDH-associated genes. Our gene ontology analysis showed that genes representing distinct biological pathways are significantly enriched in relation to different clinical presentations of CDH. This includes retinoic acid signaling in Bochdalek CDH, myogenesis in diaphragm eventration, and angiogenesis in central tendon defects. We have identified unique genotype-phenotype relationships highlighting the major genetic drivers of the different types of CDH.

Use of prostaglandin E1 to treat pulmonary hypertension in congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Prostaglandin E1 (PGE) has been used to maintain ductus arteriosus patency and unload the suprasystemic right ventricle (RV) in neonates with congenital diaphragmatic hernia (CDH) and severe pulmonary hypertension (PH). Here we evaluate the PH response in neonates with CDH and severe PH treated with PGE.

METHODS

We performed a retrospective chart review of CDH infants treated at our center between 2011 and 2016. In a subset, PGE was initiated for echocardiographic evidence of severe PH, metabolic acidosis, or hypoxemia. To assess PH response, we evaluated laboratory data, including B-type natriuretic peptide (BNP) and echocardiograms before and after PGE treatment. Categorical and continuous data were analyzed with Fisher's exact tests and Mann-Whitney t-tests, respectively.

RESULTS

Fifty-seven infants were treated with PGE a mean 17 ± 2 days. BNP levels declined after 1.4 ± 0.2 days of treatment and again after 5.2 ± 0.6 days. After 6 ± 0.8 days of treatment, echocardiographic estimates of severe PH by tricuspid regurgitation jet velocity, ductus arteriosus direction, and ventricular septum position also improved significantly. Treatment was not associated with postductal hypoxemia or systemic hypoperfusion.

CONCLUSIONS

In patients with CDH and severe PH, PGE is well tolerated and associated with improved BNP and echocardiographic indices of PH, suggesting successful unloading of the RV.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

Liver heterotopia associated with congenital diaphragmatic hernia: Two case reports and a review of the literature

RATIONALE

Liver heterotopia associated with congenital diaphragmatic hernia (CDH) is a rare condition; to the best of our knowledge, only 17 cases have been reported to date. The histogenesis and clinicopathological features are largely unknown. We herein report 2 cases of liver heterotopia associated with CDH along with 17 cases described in the literature to shed light on their clinicopathological characteristics.

PATIENT CONCERNS

Case 1 was a vaginally delivered male newborn who presented with respiratory distress immediately after birth. Case 2 was a female fetus who was found to have left-sided CDH during gestation.

DIAGNOSIS

In case 1, a chest X-ray revealed left-sided CDH. In case 2, magnetic resonance imaging performed at 33 weeks of gestation revealed left-sided CDH.

INTERVENTIONS

Case 1 underwent diaphragmatic patch repair surgery 3 days after birth. Histopathological examination following surgery in case 1 revealed the presence of ectopic liver tissue in the hernia sac. Case 2 was delivered by Cesarean section, and diaphragmatic patch surgery was performed 3 days after birth. During surgery, an isolated nodule was identified on the peritoneal side of the border of the defective foramen of the diaphragm. Histopathological examination following surgery in case 2 confirmed the presence of an epidermal cyst in the hernia sac. In addition, the isolated nodule was histopathologically found to be ectopic liver tissue.

OUTCOMES

In Case 1, CDH recurred at 6 months after surgery, and a second patch repair surgery was performed. The surgically removed hernia sac was found to contain microscopic ectopic liver tissue on histopathology. Case 1 recovered well after surgery, and there was no critical change during the 10-month postoperative period. Case 2 recovered well after surgery, and there was no critical change during the 20-month postoperative period.

LESSONS

There were no secondary pathological conditions associated with the presence of ectopic liver in CDH, such as torsion, infarction, rupture, intra-abdominal bleeding, or tumorization. Our observations suggest that liver heterotopia is a rare but asymptomatic condition in patients with CDH.

Validation of a Low-Cost Do-It-Yourself Model for Neonatal Thoracoscopic Congenital Diaphragmatic Hernia Repair

OBJECTIVE

We aimed to develop and validate a low cost, do-it-yourself model for neonatal thoracoscopic congenital diaphragmatic hernia (CDH).

DESIGN

Volunteers with varying skills in neonatal minimally invasive surgery tested and evaluated the model simulating a neonatal thoracoscopic CDH repair. The model was built from ordinary materials purchased in a dime store: a small food container, a neoprene band simulating a diaphragm, an inflated balloon simulating a spleen, a tissue chord simulating intestine, and a body wash sponge simulating a collapsed lung. The evaluation comprised 3 sets of 5-point grading scale concerning appearance, necessary maneuvers, and ability to generate skills. Bowel reduction and suture efficacy was verified for each test.

SETTING

Minimally invasive surgery simulation room at Pediatric Surgery Department of Hospital Universitario de Vall d'Hebron, Barcelona, Spain.

PARTICIPANTS

Volunteer residents and specialists of pediatric surgery.

RESULTS

Bowel reduction was possible in every test, with 1 spleen rupture, 1 bowel entrapment, and 2 inappropriate sutures due to tension. Most volunteers considered the general endoscopic vision (63.2%), external and internal dimensions (both 89.5%) to be highly similar; bowel reduction (68.4%) and diaphragm's manipulation and suture (57.9%) to be highly or very highly similar. Regarding its ability to generate skills, most considered it to be very or extremely useful concerning: camera handling (52.6%), working in small spaces and suture (both 100%), and tissue handling (63.2%). The least liked features were the colors and the diaphragm's tension. The size, portability, and the reproducibility were the most liked features.

CONCLUSIONS

We consider this low cost and easily reproducible model to be realistic enough for CDH repair training, having the potential to be adapted for other simulations.

Upregulated EFNB2 and EPHB4 promotes lung development in a nitrofen-induced congenital diaphragmatic hernia rat model

Congenital diaphragmatic hernia (CDH) is a common congenital malformation associated with high mortality rates, mainly due to pulmonary hypoplasia and persistent pulmonary hypertension following birth. The present study aimed to investigate abnormal lung development in a rat CDH model, and examine temporal and spatial changes in the expression of ephrin type‑B receptor 4 (EPHB4) and ephrin‑B2 (EFNB2) during fetal lung development, to elucidate the role of these factors during lung morphogenesis. Pregnant rats received nitrofen on embryonic day (E) 8.5 to induce CDH, and fetal lungs were collected on E13.5, E15.5, E17.5, E19.5, and E21.5. The mean linear intercept (MLI) and mean alveolar number (MAN) were observed in fetal lung tissue at E21.5 following hematoxylin and eosin staining. E13.5 fetal lungs were cultured for 96 h in serum‑free medium and branch development was observed under a microscope. The gene and protein expression levels of EPHB4 and EFNB2 were assessed by reverse transcription‑quantitative polymerase chain reaction analysis, and immunoblotting and immunohistochemistry, respectively. The fetal rat lungs were treated with EFNB2 and the activity of key signaling pathways was assessed. The lung index (lung weight/body weight) at E21.5 was significantly lower in the CDH rats, compared with that in the control fetal rats. The MLI and MAN were also lower in the CDH group. The number of lung terminal buds at E13.5 (embryonic stage), and the lung‑explant perimeter and surface were all smaller in the CDH group rats than in the control group at the same age. Pulmonary hypoplasia was observed following 96 h of in vitro culture. No significant differences were found in the expression levels of EFNB2 and EPHB4 between the CDH and control groups at E13.5 (embryonic stage) or E15.5 (pseudoglandular stage), however, EFNB2 and EPHB4 were significantly upregulated at E17.5 (canalicular stage), and at E19.5 and E21.5 (saccular/alveolar stages). EFNB2 stimulated pulmonary branching and EFNB2 supplementation decreased the activity of p38, c‑Jun NH2‑terminal kinase, extracellular signal‑regulated kinase, and signal transducer and activator of transcription. The CDH fetal rats developed pulmonary dysplasia at an early stage of fetal pulmonary development. Upregulated expression of EFNB2 and EPHB4 was observed in the rat lung of nitrofen‑induced CDH, and the increased expression of EFNB2 promoted rat lung development in the nitrofen‑induced CDH model.

Fetal interventional procedures and surgeries: a practical approach

The identification of congenital birth defects and fetal malformations continues to increase during the antenatal period with improved imaging techniques. Understanding of how to treat specific fetal conditions continues to improve outcomes from these treatment modalities. In an effort to further improvement in this field, we provide a review that begins with a brief background of fetal surgery including the history of fetal surgery, ethics surrounding fetal surgery, and considerations of how to treat the fetus during intervention. A synopsis of the most commonly encountered disease processes treated by fetal intervention/surgery including definitions, treatment modalities, and outcomes following fetal intervention/surgery is then provided. Within the sections describing each disease process, methodology is described that has helped with efficiency and success of procedures performed at our institution.

Treprostinil Improves Persistent Pulmonary Hypertension Associated with Congenital Diaphragmatic Hernia

OBJECTIVE

To evaluate the effect of continuous treprostinil in infants with severe pulmonary hypertension associated with congenital diaphragmatic hernia (CDH) on specific markers of pulmonary hypertension severity and to report the safety and tolerability of treprostinil.

STUDY DESIGN

We conducted a retrospective cohort study of infants with CDH-associated pulmonary hypertension treated with treprostinil from January 2011 to September 2016. Severity of pulmonary hypertension was assessed by echocardiogram and serum B-type natriuretic peptide (BNP) by using time points before initiation and 24 hours, 1 week, and 1 month after treprostinil initiation. Fisher exact tests, Wilcoxon-rank sum tests, and mixed-effects models were used for analysis.

RESULTS

Seventeen patients were treated with treprostinil for a median of 54.5 days (IQR 44.3-110 days). Compared with the concurrent CDH population (n = 147), infants treated with treprostinil were more likely to require extracorporeal support (76.5% vs 25.2%, P < .0001), to have a longer hospital stay (144 vs 60 days, P < .0001), and to need longer mechanical ventilator support (76.5 vs 30.9 days, P < .0001). Following treprostinil initiation, there was a significant reduction in BNP at 1 week (1439 vs 393 pg/mL, P < .01) and 1 month (1439 vs 242 pg/mL, P = .01). Severity of pulmonary hypertension by echocardiogram improved at 1 month (OR 0.14, CI 95% 0.04-0.48, P = .002). Despite these improvements, overall mortality remained high (35%). There were no adverse events related to treprostinil, including no hypotension, hypoxia, or thrombocytopenia.

CONCLUSIONS

In this cohort, treprostinil use was associated with improved severity of pulmonary hypertension assessed by echocardiogram and decreased BNP, with no significant side effects.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prenatal Diagnosis of Congenital Diaphragmatic Hernia: Does Laterality Predict Perinatal Outcomes?

OBJECTIVE

The objective of this study was to examine laterality as a predictor of outcomes among fetuses with prenatally diagnosed congenital diaphragmatic hernia (CDH).

METHODS

This is a retrospective cohort study of pregnancies with CDH evaluated at our center from 2008 to 2016 compared cases with right-sided CDH (RCDH) versus left-sided CDH (LCDH). The primary outcome was survival to discharge. Secondary outcomes included ultrasound predictors of poor prognosis (liver herniation, stomach herniation, lung area-to-head circumference ratio [LHR]), concurrent anomalies, hydrops, stillbirth, preterm birth, mode of delivery, small for gestational age, use of extracorporeal membrane oxygenation, and length of stay. Terminations and stillbirths were excluded from analyses of neonatal outcomes.

RESULTS

In this study, 157 (83%) LCDH and 32 (17%) RCDH cases were identified. Survival to discharge was similar (64 vs. 66.4%, p = 0.49) with regard to laterality. RCDH had higher rates of liver herniation (90.6 vs. 72%, p = 0.03), hydrops fetalis (15.6 vs. 1.3%, p < 0.01), and lower LHR (0.87 vs. 0.99, p = 0.04). LCDH had higher rates of stomach herniation (69.4 vs. 12.5%, p < 0.01). Rates of other outcomes were similar in univariate analyses. Adjusting for microarray abnormalities, the odds for survival to discharge for RCDH compared with LCDH was 0.93 (0.38-2.30, p = 0.88).

CONCLUSION

Compared with LCDH, fetuses with RCDH had higher rates of adverse ultrasound predictors, but equivalent survival.

MicroRNA 200b is upregulated in the lungs of fetal rabbits with surgically induced diaphragmatic hernia

OBJECTIVE

Profiling of miR-200b expression and its targets (transforming growth factor [TGF]-β2 and ZEB2) in the surgical rabbit congenital diaphragmatic hernia (DH) model before and after tracheal occlusion (TO).

METHODS

Thirty-eight timed-pregnant rabbits had left DH creation on gestational day (GD) 23. On GD28, 17 randomly selected fetuses had TO. We harvested fetuses at GD23, GD28, or GD30. We calculated lung-to-body weight ratios, processed lungs for miR-200b in situ hybridization and real-time quantitative polymerase chain reaction, and evaluated effects on downstream targets TGF-β2 or ZEB2.

RESULTS

We obtained 16 DH fetuses (n = 7 GD28 and n = 9 GD30), 13 TO fetuses (GD30), and 38 control fetuses (n = 15 GD23, n = 11 GD28, and n = 12 GD30). Diaphragmatic hernia lungs were hypoplastic, and TO resulted in control lung-to-body weight ratio levels. Term miR-200b-3p levels were significantly upregulated in the hypoplastic compared with control ipsilateral lung (1.906 ± 0.90 vs 0.7429 ± 0.44) (P < .01). Fetal TO ipsilateral lungs displayed a variable miR-200b response on in situ hybridization and polymerase chain reaction, with levels similar to control and congenital DH lungs. The TGF-β2 was unchanged in hypoplastic and TO lungs, and ZEB2 tended to be reduced in TO compared with DH lungs (1.79 [0.4-2.9] vs 0.73 [0.5-1.4]).

CONCLUSIONS

Hypoplastic fetal rabbit lungs display upregulation of miR-200b expression although downstream targets are not different from controls. Following TO, fetal rabbit lungs display a variable miR-200b response.

Systematic analysis of copy number variation associated with congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH), characterized by malformation of the diaphragm and hypoplasia of the lungs, is one of the most common and severe birth defects, and is associated with high morbidity and mortality rates. There is growing evidence demonstrating that genetic factors contribute to CDH, although the pathogenesis remains largely elusive. Single-nucleotide polymorphisms have been studied in recent whole-exome sequencing efforts, but larger copy number variants (CNVs) have not yet been studied on a large scale in a case control study. To capture CNVs within CDH candidate regions, we developed and tested a targeted array comparative genomic hybridization platform to identify CNVs within 140 regions in 196 patients and 987 healthy controls, and identified six significant CNVs that were either unique to patients or enriched in patients compared with controls. These CDH-associated CNVs reveal high-priority candidate genes including HLX, LHX1, and HNF1B We also discuss CNVs that are present in only one patient in the cohort but have additional evidence of pathogenicity, including extremely rare large and/or de novo CNVs. The candidate genes within these predicted disease-causing CNVs form functional networks with other known CDH genes and play putative roles in DNA binding/transcription regulation and embryonic development. These data substantiate the importance of CNVs in the etiology of CDH, identify CDH candidate genes and pathways, and highlight the importance of ongoing analysis of CNVs in the study of CDH and other structural birth defects.

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.

Nonisolated diaphragmatic hernia in Simpson-Golabi-Behmel syndrome

OBJECTIVE

Congenital diaphragmatic hernia (CDH) is associated with Simpson-Golabi-Behmel syndrome (SGBS), but few cases diagnosed prenatally have been reported. The aim of this series is to highlight the association of nonisolated CDH with SGBS type I on prenatal ultrasound and emphasize the importance of genetic testing, fetal autopsy, and family history in confirming this diagnosis.

METHOD

Retrospective review of 3 cases of SGBS type I in a single tertiary care centre. Family history, fetal ultrasound, autopsy findings, and genetic testing for GPC3 was performed for each case.

RESULTS

Fetal ultrasound findings in the second trimester were CDH, omphalocele, increased nuchal fold, renal anomaly, and cleft lip and palate. Fetal autopsy confirmed the prenatal ultrasound findings and also showed dysmorphic facial features and premalignant lesions on renal and gonadal histology. Microarray and DNA analysis of the GPC3 gene confirmed the diagnosis of SGBS type I in each case.

CONCLUSION

Nonisolated CDH in a male fetus suggests a diagnosis of SGBS type I. Fetal autopsy, pedigree analysis, and genetic testing for GPC3 are all essential to confirming the diagnosis. The histological findings of ovotestes and nephroblastomatosis indicate that cancer predisposition is established early in fetal life.

Pulmonary vascular development in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly characterised by a diaphragmatic defect, persistent pulmonary hypertension (PH) and lung hypoplasia. The relative contribution of these three elements can vary considerably in individual patients. Most affected children suffer primarily from the associated PH, for which the therapeutic modalities are limited and frequently not evidence based. The vascular defects associated with PH, which is characterised by increased muscularisation of arterioles and capillaries, start to develop early in gestation. Pulmonary vascular development is integrated with the development of the airway epithelium. Although our knowledge is still incomplete, the processes involved in the growth and expansion of the vasculature are beginning to be unravelled. It is clear that early disturbances of this process lead to major pulmonary growth abnormalities, resulting in serious clinical challenges and in many cases death in the newborn. Here we provide an overview of the current molecular pathways involved in pulmonary vascular development. Moreover, we describe the abnormalities associated with CDH and the potential therapeutic approaches for this severe abnormality.