Congenital diaphragmatic hernia and pulmonary hypoplasia: new insights from developmental biology and genetics

Radiomics-Assisted Computed Tomography-Based Analysis to Evaluate Lung Morphology Characteristics after Congenital Diaphragmatic Hernia

Purpose: Children with congenital diaphragmatic hernia suffer from long-term morbidity, including lung function impairment. Our study aims to analyze lung morphology characteristics via radiomic-assisted extraction of lung features in patients after congenital diaphragmatic hernia repair. Materials and Methods: 72 patients were retrospectively analyzed after approval by the local research ethics committee. All the image data were acquired using a third-generation dual-source CT (SOMATOM Force, Siemens Healthineers, Erlangen, Germany). Dedicated software was used for image analysis, segmentation, and processing. Results: Radiomics analysis of pediatric chest CTs of patients with status after CDH was possible. Between the ipsilateral (side of the defect) and contralateral lung, three shape features and two higher-order texture features were considered statistically significant. Contralateral lungs in patients with and without ECMO treatment showed significant differences in two shape features. Between the ipsilateral lungs in patients with and without the need for ECMO 1, a higher-order texture feature was depicted as statistically significant. Conclusions: By adding quantitative information to the visual assessment of the radiologist, radiomics-assisted feature analysis could become an additional tool in the future to assess the degree of lung hypoplasia in order to further improve the therapy and outcome of CDH patients.

Critical functional lung volumes in neonatal intensive care: evidence and clinical applications

Respiratory disease is common in premature and sick newborn infants and can often necessitate the initiation of intensive care. Newborn infants often suffer from conditions that are associated with decreased lung volumes that occur as a result of abnormal or incomplete lung development. Such conditions are prematurity and respiratory distress syndrome, preterm premature rupture of membranes and the ensuing pulmonary hypoplasia and congenital lung anomalies such as congenital diaphragmatic hernia. These diseases have a structural component manifesting with lower lung volumes and a functional component that can present with increased oxygen and ventilatory requirements. The corresponding decreased functional lung volume is possibly responsible for some unfavourable pulmonary outcomes. Some infants are unable to wean off invasive respiratory support and, in extreme cases, unable to sustain independent breathing that can lead to long-term invasive ventilation or subsequent death. The aim of this review is to summarise the available evidence behind the concept of a critical functional lung volume in neonatal intensive care and describe the clinical implications that arise from decreased functional lung volumes in the main high-risk populations of newborn infants. IMPACT: Newborn infants suffer from diseases such as respiratory distress syndrome, pulmonary hypoplasia and congenital diaphragmatic hernia that are associated with a decrease in the total lung volume and impaired lung function. Critically decreased functional lung volumes during neonatal care are associated with failure to wean off invasive respiratory support, increased mortality and possibly longer-term respiratory complications.

Effect of Chest Resistance and Expansion Exercises on Respiratory Muscle Strength, Lung Function, and Thoracic Excursion in Children with a Post-Operative Congenital Diaphragmatic Hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a life-threatening condition with long-term complications including respiratory tract infections, respiratory muscle weakness, and abnormal lung functions. This study was designed to ascertain the effects of chest resistance and chest expansion exercises on respiratory muscle strength, lung function, and chest mobility in children with post-operative CDH.

METHODS

This randomized controlled clinical study was conducted in the outpatient physiotherapy clinic at Prince Sattam bin Abdulaziz University. Thirty-two children with CDH aged 10-14 years between May 2020 and February 2021 were randomly allocated to the study group (n = 16) and the control group (n = 16). The control group underwent a usual chest physiotherapy program; however, the study group underwent a 12-week chest resistance exercise combined with chest expansion exercise in addition to usual chest physiotherapy, with three sessions per week. Respiratory muscle strength, lung function, and thoracic excursion were assessed pre- and post-treatment.

RESULTS

Using the 2 × 2 repeated ANOVA, significant time × group interactions were detected in favor of the study group, FVC (F = 4.82, 95% CI = -15.6 to -0.97, p = 0.005, and η² = 0.16), FEV1 (F = 4.54, 95% CI = -11.99 to -2.8, p ˂ 0.001, and η² = 0.14), PImax (F = 5.12, 95% CI = -15.71 to -5.3, p ˂ 0.001, and η² = 0.15), and thoracic excursion (F = 4.41, 95% CI = -2.04 to -0.16, p = 0.036, and η² = 0.17).

CONCLUSIONS

Concurrent chest resistance and expansion exercises may improve respiratory muscle strength, lung function, and thoracic excursion in children with post-operative CDH. The study findings suggest that concurrent chest and chest expansion exercises be part of an appropriate pulmonary rehabilitation program in children with a history of CDH.

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.

Bochdalek hernias associated with intrathoracic kidney: A case report and systematic review of outcomes including renal function

Background: An intrathoracic kidney is a very rare form of ectopic kidney. Though increasingly recognized in the literature, impact on renal function is less well described. We report the case of a 67-year-old South Asian gentleman who presented with intrathoracic kidney and chronic kidney disease. We carried out a systematic review of the available literature on intrathoracic kidney, in order to characterize the typical clinical features, and describe likely clinical course and possible renal and extra-renal complications associated with this form of ectopia. Materials and methods: A structured search using PubMed identified all relevant published case reports from 1988 to 2018, with search restricted to papers in English, and to adult cases only (> 18 years of age). 124 records were identified, and after screening for eligibility, 34 case reports were analyzed. Results: Median age was 53.5 years, with no gender predominance. 68% (27/34) of cases were symptomatic. 29% (10/34) had a significant complication associated with their intrathoracic kidney, with 3 cases with either documented chronic or end-stage kidney disease. 26% (9/34) required surgical intervention. Conclusion: Though previously regarded as a benign entity, results from our systematic review, bearing in mind susceptibility to publication bias, suggests an appreciable risk of symptoms, complications, and in the minority a risk to kidney function. We recommend close biochemical and imaging surveillance of affected patients, with low threshold for intervention in those with renovascular stenosis, reflux, or hydronephrosis.

Lung function in school-aged congenital diaphragmatic hernia patients; a longitudinal evaluation

OBJECTIVE

Children with congenital diaphragmatic hernia (CDH) are at risk for pulmonary morbidity. Data on longitudinal evaluation of lung function in CDH are scarce. We hypothesized that CDH patients would have impaired lung function that worsens over time. We evaluated lung function and its determinants at ages 8 and 12 years.

METHODS

Dynamic and static lung volumes, and diffusion capacity were measured. Extracorporeal membrane oxygenation (ECMO) treatment, the standardized European neonatal treatment protocol, patch repair, duration of ventilation, type of initial mechanical ventilation, and nitric oxide treatment were entered as covariates in linear mixed models with standard deviation score (SDS) lung function parameters (FEV₁ , FEF _25-75 , and K _CO ) as dependent variables.

RESULTS

Seventy-six children (27 ECMO-treated) born between 1999 and 2009 performed 113 reliable lung function tests. Severity of airflow obstruction deteriorated significantly from age 8 to 12 years: estimated mean difference (95% confidence interval [CI]) SDS FEV₁ was -0.57 (-0.79 to -0.36) and SDS FEF_25-75 was -0.63 (-0.89 to -0.37), both P < .001. Static lung volumes were within normal range and unchanged over time: estimated mean difference (95% CI) SDS TLC -0.27 (-0.58 to 0.04); P = .085. SDS K_CO was below normal at 8 and 12 years and remained stable: -0.06 (-0.22 to 0.35); P = .648. These observations were irrespective of ECMO treatment. FEV₁ and FEF_25-75 were negatively associated with duration of ventilation (P < .001). Baseline data were not related with TLC or K_CO. CONCLUSIONS: CDH patients should be followed into adulthood as they are at risk for worsening airflow obstruction and decreased diffusion capacity at school age, irrespective of ECMO treatment.

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.

Congenital diaphragmatic hernia and exercise capacity, a longitudinal evaluation

OBJECTIVE

Children with congenital diaphragmatic hernia (CDH) suffer from long-term pulmonary morbidity. Longitudinal data of exercise capacity in these children are lacking. We hypothesized that exercise capacity would be impaired in children with CDH and deteriorates over time. We evaluated exercise capacity and its determinants in CDH patients longitudinally until 12 years of age.

DESIGN

Prospective longitudinal follow-up study in tertiary university hospital.

PATIENTS

One hundred and fourteen children with CDH born between 1999 and 2012.

METHODS

Exercise capacity was evaluated using the Bruce treadmill-protocol at the ages of 5, 8, and 12 years. Primary outcome parameter was standard deviation score (SDS) of maximal endurance time. Data were analyzed by using linear mixed models.

RESULTS

A total of 107 children (30 treated with extracorporeal membrane oxygenation [ECMO]) performed 191 reliable exercise tests. At ages 5, 8, and 12 years, the mean (95%CI) SDS endurance time was -0.44 (-0.65 to -0.24); -1.01 (-1.23 to -0.78); -1.10 (-1.40 to -0.80), respectively, all less than zero (P < 0.001). Exercise capacity declined significantly over time irrespective of ECMO-treatment (5-12 years: non-ECMO P = 0.015; ECMO P = 0.006). Duration of initial hospital stay and diffusion capacity corrected for alveolar volume were associated with SDS endurance time (P < 0.001 and P = 0.039).

CONCLUSIONS

In CDH patients exercise capacity deteriorates between 5 and 12 years of age, irrespective of ECMO-treatment. CDH patients may benefit from long-term assessments of exercise capacity with timely intervention.

Pulmonary Hypertension in Patients with Congenital Diaphragmatic Hernia: Does Lung Size Matter?

PURPOSE

 The relationship between pulmonary hypoplasia and pulmonary arterial hypertension (PHTN) in patients with congenital diaphragmatic hernia (CDH) remains ill-defined. We hypothesized that prenatal estimates of lung size would directly correlate with PHTN severity.

METHODS

 Infants with isolated CDH (born 2004-2015) at a single institution were included. Estimates of lung size included observed-to-expected LHR (o:eLHR) and %-predicted lung volumes (PPLV = observed/predicted volumes). The primary outcome was severity of PHTN (grade 0-3) on echocardiography performed between day of life 3 and 30.

RESULTS

 Among 62 patients included, there was 32% mortality and 65% ECMO utilization. PPLV (odds ratio [OR] = 0.94 per 1 grade in PHTN severity, 95% confidence interval [CI] = 0.89-0.98, p < 0.01) and o:eLHR (OR = 0.97, 95% CI = 0.94-0.99, p < 0.01) were significantly associated with PHTN grade. Among patients on ECMO, PPLV (OR = 0.92, 95% CI = 0.84-0.99, p = 0.03) and o:eLHR (OR = 0.95, 95% CI = 0.92-0.99, p = 0.01) were more strongly associated with PHTN grade. PPLV and o:eLHR were significantly associated with the use of inhaled nitric oxide (iNO) (OR = 0.90, 95% CI = 0.83-0.98, p = 0.01 and OR = 0.94, 95% CI = 0.91-0.98, p < 0.01, respectively) and epoprostenol (OR = 0.91, 95% CI = 0.84-0.99, p = 0.02 and OR = 0.93, 95% CI = 0.89-0.98, p < 0.01, respectively).

CONCLUSION

 Among infants with isolated CDH, PPLV, and o:eLHR were significantly associated with PHTN severity, especially among patients requiring ECMO. Prenatal lung size may help predict postnatal PHTN and associated therapies.

Lung function and pulmonary artery blood flow following prenatal maternal retinoic acid and imatinib in the nitrofen model of congenital diaphragmatic hernia

BACKGROUND

Lung and pulmonary vascular maldevelopment in congenital diaphragmatic hernia (CDH) results in significant morbidity and mortality. Retinoic acid (RA) and imatinib have been shown to improve pulmonary morphology following prenatal administration in the rat nitrofen-induced CDH model. It remains unclear if these changes translate into improved function. We evaluated the effect of prenatal RA and imatinib on postnatal lung function, structure, and pulmonary artery (PA) blood flow in the rat CDH model.

METHODS

Olive oil or nitrofen was administered alone or in combination with RA or imatinib to pregnant rats. Pups were assessed for PA blood flow by ultrasound and pulmonary function/morphology following delivery, intubation, and short-term ventilation.

RESULTS

Neither RA nor imatinib had a negative effect on lung and body growth. RA accelerated lung maturation indicated by increased alveoli number and thinner interalveolar septa and was associated with decreased PA resistance and improved oxygenation. With the exception of a decreased PA pulsatility index, no significant changes in morphology and pulmonary function were noted following imatinib.

CONCLUSION

Prenatal treatment with RA but not imatinib was associated with improved pulmonary morphology and function, and decreased pulmonary vascular resistance. This study highlights the potential of prenatal pharmacologic therapies, such as RA, for management of CDH.

Cerebral Perfusion After Repair of Congenital Diaphragmatic Hernia with Common Carotid Artery Occlusion After ECMO Therapy

AIM

To prospectively evaluate cerebral perfusion after repair of congenital diaphragmatic hernia (CDH) and right-common-carotid-artery (rCCA) occlusion after extracorporeal membrane oxygenation (ECMO) therapy.

PATIENTS AND METHODS

A total of 29 2-year-old-children with a history of CDH repair underwent cerebral magnetic resonance perfusion imaging. In 14 patients, the rCCA was occluded after ECMO therapy. Fifteen patients with CDH without ECMO served as controls. Regional cerebral-blood-flow (rCBF) was measured cortically and subcortically in both hemispheres and compared intra-individually and between both groups.

RESULTS

Patients with rCCA-occlusion showed intra-individual side differences between hemispheres, with significantly lower subcortical perfusion of the right hemisphere and reduced cortical perfusion. In one-third of patients with rCCA-occlusion, rCBF of the right-hemisphere was reduced by more than 20% when compared to the left hemisphere. Despite intra-individual side differences, mean rCBF in patients with rCCA occlusion was not reduced compared to controls.

CONCLUSION

Beside intra-individual side differences, overall right hemisphere perfusion is sufficient after rCCA-occlusion due to collateral blood supply.

Early development of pleuroperitoneal fold of the diaphragm in the rat fetus

The embryonic diaphragm comprises four major structural components derived from the transverse septum, the dorsal foregut mesentery, the pleuroperitoneal folds (PPFs), and the body wall. In this study, the appearance of PPFs and related factors were investigated using light microscopy of horizontal sections of rat fetuses from embryonic day 12 to 13. In rat fetuses, the sign of PPF projection was noted in the sidewall of the pericardioperitoneal canal at embryonic day 12, and was confirmed as folds at embryonic day 12.25. Expressions of GATA4, COUP-TF2, and FOG2 were detected in PPF at the early stage of formation. Localizations of these factors suggested that COUP-TF2 and FOG2 are the main factors in PPF appearance and that GATA4 is unlikely to be a main factor, although it is necessary for PPF formation.

A novel multimodal computational system using near-infrared spectroscopy predicts the need for ECMO initiation in neonates with congenital diaphragmatic hernia

BACKGROUND/PURPOSE

The purpose of this study was to develop a computational algorithm that would predict the need for ECMO in neonates with congenital diaphragmatic hernia (CDH).

METHODS

CDH patients from August 2010 to 2016 were enrolled in a study to continuously measure cerebral tissue oxygen saturation (cStO2) of left and right cerebral hemispheres. NIRS devices utilized were FORE-SIGHT, CASMED and INVOS 5100, Somanetics. Using MATLAB©, a data randomization function was used to deidentify and blindly group patient's data files as follows: 12 for the computational model development phase (6 ECMO and 6 non-ECMO) and the remaining patients for the validation phase.

RESULTS

Of the 56 CDH patients enrolled, 22 (39%) required ECMO. During development of the algorithm, a difference between right and left hemispheric cerebral oxygenation via NIRS (ΔHCO) was noted in CDH patients that required ECMO. Using ROC analysis, a ΔHCO cutoff >10% was predictive of needing ECMO (AUC: 0.92; sensitivity: 85%; and specificity: 100%). The algorithm predicted need for ECMO within the first 12h of life and at least 6h prior to the clinical decision for ECMO with 88% sensitivity and 100% specificity.

CONCLUSION

This computational algorithm of cerebral NIRS predicts the need for ECMO in neonates with CDH.

LEVEL OF EVIDENCE

II.

Congenital Diaphragmatic Hernia with Liver Herniation into the Pericardial Sac in a 30-Week Gestation Infant

Anterior diaphragmatic defects with pericardial involvement are extremely rare and diagnostically challenging entities encountered perinatally. While a majority of diaphragmatic defects occur in isolation, others are associated with multiple defects forming a complex of syndromes such as Pentalogy of Cantrell. Liver herniation into the pericardial sac poses a particular challenge and can mimic a pericardial tumor on prenatal ultrasound, yielding a different management course. The following case is an unusual presentation of a 30-week gestation female with an anterior midline diaphragmatic defect with liver herniation mimicking as a pericardial tumor, diagnosed at time of autopsy. Postmortem studies also found multiple congenital anomalies including an atrioventricular septal defect and midline gumline defect suggesting at least a partial Pentalogy of Cantrell or variant. Early recognition and screening for associated anomalies are essential for management in this subset of patients.

Cumulative radiation exposure from imaging procedures and associated lifetime cancer risk for patients with lymphoma

The aim of this study was to systematically evaluate the cumulative radiation exposure and the associated lifetime-cancer-risk from diagnostic imaging in patients with Hodgkin-lymphoma-(HL) or diffuse-large-B-cell-lymphoma (DLBCL). 99 consecutive patients (53-males) diagnosed with HL or DLBCL were included in the study and followed. Based on the imaging reports, organ and effective-doses-(ED) were calculated individually for each patient and the excess lifetime risks were estimated. The average ED in the first year after diagnosis was significantly different for men (59 ± 33 mSv) and women (744 ± 33 mSv)-(p < 0.05). The mean cumulative ED in each of the following 5 years was 16 ± 16 mSv without significant differences between men and women-(p > 0.05). Over all years, more than 90% of the ED resulted from CT. The average cumulative radiation risk estimated for the first year was significantly lower for men (0.76 ± 0.41%) as compared to women (1.28 ± 0.54%)-(p < 0.05). The same was found for each of the subsequent 5-years (men-0.18 ± 0.17%; women-0.28 ± 0.25%)-(p < 0.05). In conclusion, for HL and DLBCL patients investigated in this study, a cumulative radiation risk of about 1 excess cancer per 100 patients is estimated for diagnostic imaging procedures performed during both the first year after diagnosis and a follow-up period of 5 years.

Separate Evaluation of the Ipsilateral and Contralateral MR Fetal Lung Volume in Patients With Congenital Diaphragmatic Hernia

OBJECTIVE

Our study had two objectives. First, we separately evaluated observed-to-expected MR fetal lung volume (FLV) of lungs ipsilateral and contralateral to a congenital diaphragmatic hernia (CDH). Second, we compared the prognostic value of observed-to-expected MR FLV of the ipsilateral and contralateral lungs with that of observed-to-expected MR FLV of both lungs with respect to survival, need for extracorporeal membrane oxygenation (ECMO), and development of chronic lung disease (CLD).

MATERIALS AND METHODS

We evaluated observed-to-expected MR FLV of the lung ipsilateral to the diaphragmatic defect as well as in the contralateral lung in 107 fetuses with isolated CDH. ROC analysis and logistic regression analysis were performed to assess the prognostic value of the observed-to-expected MR FLV for association with outcome.

RESULTS

In all fetuses with CDH, values in the ipsilateral (mean observed-to-expected MR FLV ± SD, 9.4% ± 9.6%) and the contralateral lung (mean observed-to-expected MR FLV, 48.9% ± 18.5%; p < 0.0001) were significantly lower than values measured in healthy fetuses. Observed-to-expected MR FLV of both lungs and of the contralateral and ipsilateral lung revealed significant differences regarding survival (p < 0.0001, p < 0.0001, and p = 0.0170, respectively), need for ECMO (p < 0.0001, p < 0.0001, and p = 0.0051, respectively), and development of CLD (p = 0.0004, p = 0.0002, and p = 0.0460, respectively). Compared with the observed-to-expected MR FLV of both lungs, the observed-to-expected MR FLV of the contralateral lung showed a slightly higher prognostic accuracy regarding survival (AUC = 0.859 vs 0.825) and development of CLD (AUC = 0.734 vs 0.732) and a similar prognostic accuracy regarding need for ECMO (AUC = 0.805 vs 0.826). Observed-to-expected MR FLV of the ipsilateral lung did not show good prognostic value regarding survival (AUC = 0.617), need for ECMO (AUC = 0.673), and development of CLD (AUC = 0.636). These AUCs were significantly smaller than the AUCs resulting from the observed-to-expected MR FLV of both lungs (each p < 0.05) and considerably smaller than the AUCs of the observed-to-expected MR FLV of the contralateral lung (each p < 0.10).

CONCLUSION

Patients with CDH showed a substantially lower observed-to-expected MR FLV of both lungs compared with healthy fetuses. The observed-to-expected MR FLV of both lungs as well as of the lung contralateral to the CDH were reliable prenatal predictors of survival, need for ECMO, and development of CLD.

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

INTRODUCTION

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

CASE PRESENTATION

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

CONCLUSIONS

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

Space occupying lesions in the presence of congenital diaphragmatic hernia

INTRODUCTION

Previous reports describe lung malformations and other chest lesions in association with congenital diaphragmatic hernia (CDH), yet little is known how these lesions affect outcomes. We sought to evaluate the incidence and outcomes of patients diagnosed with chest lesions in association with CDH.

METHODS

The charts of all infants treated for CDH in a single tertiary center from January 2004 to January 2015 were reviewed. The outcomes of those with space occupying lesions (SOLs) in association with CDH were compared to those with isolated CDH. Statistical analysis was performed using Student's t-test and Mann-Whitney U test for continuous variables and Fisher's exact for categorical variables.

RESULTS

Of the 214 infants treated, 20 had an associated SOL (4 had>1 lesion). SOLs were confirmed by pathological examination and included: bronchopulmonary sequestration (n=10; 4.7%), ectopic liver (n=9; 4.2%), foregut duplication cyst (n=2; 1%), and other lesions (n=3; 1.4%). No statistical difference was noted in the long-term outcomes of patients with SOL in comparison to those with isolated CDH.

CONCLUSION

SOLs are not uncommon in neonates with CDH. Despite theoretical concerns, there is no evidence that SOLs are associated with worse outcomes, a finding which is helpful during prenatal counseling of families.

Patterns of fetal lung growth in fetuses with isolated left-sided congenital diaphragmatic hernia

OBJECTIVE

To evaluate right lung growth pattern in fetuses with isolated left-sided congenital diaphragmatic hernia (iL-CDH) and to analyze the pattern according to postnatal outcome.

METHODS

Lung-to-head ratio (LHR) and observed-to-expected LHR (O/E LHR) were obtained in 58 cases. Correlation and regression analysis for the total number of measurements, general linear models for those cases with a least three serial measurements and linear mixed effect models were used to analyze the influence of gestational age on the right lung size. Cases expectantly managed and those with fetal endoscopic tracheal occlusion were analyzed separately.

RESULTS

LHR, but not O/E LHR, increased significantly with gestational age (GA) (r = 0.43, p = 0.003 and r = -0.13, p = 0.30, respectively). According to neonatal mortality, in those fetuses that died, LHR remained unchanged and O/E LHR decreased significantly with GA (r = 0.07, p = 0.65 and r = -0.37, p = 0.02, respectively). In those cases with at least three serial measurements, the same two patterns were found. Similarly, in cases with expectant management, surviving fetuses showed a significantly higher weekly increase in LHR (p = 0.01) and a trend to a lower weekly decrease in O/E LHR (p = 0.17) than in those that died.

CONCLUSIONS

Patterns of right lung growth in iL-CDH differ according to postnatal survival. Serial measurements, but not a single one, might increase the prediction of neonatal death.

Prenatal MR imaging of congenital diaphragmatic hernias: association of MR fetal lung volume with the need for postnatal prosthetic patch repair

OBJECTIVE

To assess whether the need for postnatal prosthetic patch repair of the diaphragmatic defect in neonates with a congenital diaphragmatic hernia (CDH) is associated with the antenatal measured observed-to-expected magnetic resonance fetal lung volume (o/e MR-FLV).

METHODS

The o/e MR-FLV was calculated in 247 fetuses with isolated CDH. Logistic regression analysis was used to assess the prognostic value of the individual o/e MR-FLV for association with the need for postnatal patch repair.

RESULTS

Seventy-seven percent (77%) of patients with a CDH (190/247) required prosthetic patch repair and the defect was closed primarily in 23% (57/247). Patients requiring a patch had a significantly lower o/e MR-FLV (27.7 ± 10.2%) than patients with primary repair (40.8 ± 13.8%, p < 0.001, AUC = 0.786). With an o/e MR-FLV of 20%, 92% of the patients required patch repair, compared to only 24% with an o/e MR-FLV of 60%. The need for a prosthetic patch was further influenced by the fetal liver position (herniation/no herniation) as determined by magnetic resonance imaging (MRI; p < 0.001). Fetal liver position, in addition to the o/e MR-FLV, improves prognostic accuracy (AUC = 0.827).

CONCLUSION

Logistic regression analysis based on the o/e MR-FLV is useful for prenatal estimation of the prosthetic patch requirement in patients with a CDH. In addition to the o/e MR-FLV, the position of the liver as determined by fetal MRI helps improve prognostic accuracy.

KEY POINTS

• The o/e MR-FLV is associated with the need for postnatal patch repair in CDH. • The need for a patch is associated with a significantly lower o/e MR-FLV (p < 0.001). • The patch requirement is also influenced by fetal liver position. • Fetal liver position, in addition to the o/e MR-FLV, improves prognostic accuracy. • CDH-fetuses with a high probability for patch requirement can be identified prenatally.

Prenatal MRI fetal lung volumes and percent liver herniation predict pulmonary morbidity in congenital diaphragmatic hernia (CDH)

PURPOSE

The purpose of this study was to determine whether prenatal imaging parameters are predictive of postnatal CDH-associated pulmonary morbidity.

METHODS

The records of all neonates with CDH treated from 2004 to 2012 were reviewed. Patients requiring supplemental oxygen at 30 days of life (DOL) were classified as having chronic lung disease (CLD). Fetal MRI-measured observed/expected total fetal lung volume (O/E-TFLV) and percent liver herniation (%LH) were recorded. Receiver operating characteristic (ROC) curves and multivariate regression were applied to assess the prognostic value of O/E-TFLV and %LH for development of CLD.

RESULTS

Of 172 neonates with CDH, 108 had fetal MRIs, and survival was 76%. 82% (89/108) were alive at DOL 30, 46 (52%) of whom had CLD. Neonates with CLD had lower mean O/E-TFLV (30 vs.42%; p=0.001) and higher %LH (21.3±2.8 vs.7.1±1.8%; p<0.001) compared to neonates without CLD. Using ROC analysis, the best cutoffs in predicting CLD were an O/E-TFLV<35% (AUC=0.74; p<0.001) and %LH>20% (AUC=0.78; p<0.001). On logistic regression, O/E-TFLV<35% and a %LH>20% were highly associated with indicators of long-term pulmonary sequelae. On multivariate analysis, %LH was the strongest predictor of CLD in patients with CDH (OR: 10.96, 95%CI: 2.5-48.9, p=0.002).

CONCLUSION

Prenatal measurement of O/E-TFLV and %LH is predictive of CDH pulmonary morbidity and can aid in establishing parental expectations of postnatal outcomes.

Kif7 is required for the patterning and differentiation of the diaphragm in a model of syndromic congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common birth defect that results in a high degree of neonatal morbidity and mortality, but its pathological mechanisms are largely unknown. Therefore, we performed a forward genetic screen in mice to identify unique genes, models, and mechanisms of abnormal diaphragm development. We identified a mutant allele of kinesin family member 7 (Kif7), the disorganized diaphragm (dd). Embryos homozygous for the dd allele possess communicating diaphragmatic hernias, central tendon patterning defects, and increased cell proliferation with diaphragmatic tissue hyperplasia. Because the patterning of the central tendon is undescribed, we analyzed the expression of genes regulating tendonogenesis in dd/dd mutant embryos, and we determined that retinoic acid (RA) signaling was misregulautted. To further investigate the role of Kif7 and RA signaling in the development of the embryonic diaphragm, we established primary mesenchymal cultures of WT embryonic day 13.5 diaphragmatic cells. We determined that RA signaling is necessary for the expression of tendon markers as well as the expression of other CDH-associated genes. Knockdown of Kif7, and retinoic acid receptors alpha (Rara), beta (Rarb), and gamma (Rarg) indicated that RA signaling is dependent on these genes to promote tendonogenesis within the embryonic diaphragm. Taken together, our results provide evidence for a model in which inhibition of RA receptor signaling promotes CDH pathogenesis through a complex gene network.

Development of the diaphragm -- a skeletal muscle essential for mammalian respiration

The mammalian diaphragm muscle is essential for respiration, and thus is one of the most critical skeletal muscles in the human body. Defects in diaphragm development leading to congenital diaphragmatic hernias (CDH) are common birth defects and result in severe morbidity or mortality. Given its functional importance and the frequency of congenital defects, an understanding of diaphragm development, both normally and during herniation, is important. We review current knowledge of the embryological origins of the diaphragm, diaphragm development and morphogenesis, as well as the genetic and developmental aetiology of diaphragm birth defects.

Congenital diaphragmatic defects: proposal for a new classification based on observations in 234 patients

Congenital diaphragmatic defects (CDDs) are a common group of birth defects, yet we presently know little about their pathogenesis. No systematic study documenting the detailed morphology of CDD has been performed, and current classification schemata of diaphragm phenotypes incompletely capture the location and extent of diaphragmatic involvement. To define the range of CDD anatomy, diaphragmatic pathology was reviewed from an examination of 181 autopsy records of children with CDDs at Children's Hospital Boston between 1927 and 2006. Defects were classified according to several parameters, including type (communicating versus noncommunicating) and location (anterior, posterior, etc.). The information permitted development of a phenotyping worksheet for prospective use on patients undergoing diaphragmatic repair at Children's Hospital Boston or MassGeneral Hospital for Children. Fifty-three patients who died between 1990 and 2006 had a total of 63 defects. Thirty-nine had a "classic" CDD phenotype (64% posterolateral, 18% hemidiaphragmatic aplasia, and 18% anterior). The remaining 19 defects, not fitting classical descriptions, were located in the posteromedial, anterolateral, or lateral regions of the diaphragm. Prospective data collected during surgical repair revealed posterolateral defects in 34 of 41 cases that demonstrated wide phenotypic variability in size, location, shape, type, and extent of organ displacement. Congenital diaphragmatic defects display significant phenotypic variation. Because rigorous anatomic evaluation and documentation are important steps towards elucidating the developmental biology of these disorders, we suggest establishment of a new and more precise classification using the model presented herein.

Current advances in prenatal imaging of congenital diaphragmatic [corrected] hernia

Congenital diaphragmatic hernia, despite advances in therapy, remains a complex condition with significant morbidity and mortality. The etiology of the disorder is still incompletely understood, though the pulmonary hypoplasia and pulmonary hypertension that develop secondarily must be overcome to improve survival. Prenatal US and fetal MRI have helped in the development of a greater understanding of this disease. Also with these modalities, measurement techniques have been developed in an attempt to provide prognosticators for the development of pulmonary hypoplasia and pulmonary hypertension. There is a broad range of approaches for performing these measurements, and variability among imaging centers is noted. Despite inconsistent approaches, these techniques have become the foundation for counseling and prenatal and postnatal therapy. It is hoped that with further research with prenatal US and fetal MRI and the development of innovative medical and surgical therapies that the morbidity and mortality of children with congenital diaphragmatic hernias can be significantly reduced.

The VICI-trial: high frequency oscillation versus conventional mechanical ventilation in newborns with congenital diaphragmatic hernia: an international multicentre randomized controlled trial

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly of the diaphragm resulting in pulmonary hypoplasia and pulmonary hypertension. It is associated with a high risk of mortality and pulmonary morbidity. Previous retrospective studies have reported high frequency oscillatory ventilation (HFO) to reduce pulmonary morbidity in infants with CDH, while others indicated HFO to be associated with worse outcome. We therefore aimed to develop a randomized controlled trial to compare initial ventilatory treatment with high-frequency oscillation and conventional ventilation in infants with CDH.

METHODS/DESIGN

This trial is designed as a multicentre trial in which 400 infants (200 in each arm) will be included. Primary outcome measures are BPD, described as oxygen dependency by day 28 according to the definition of Jobe and Bancalari, and/or mortality by day 28. All liveborn infants with CDH born at a gestational age of over 34 weeks and no other severe congenital anomalies are eligible for inclusion. Parental informed consent is asked antenatally and the allocated ventilation mode starts within two hours after birth. Laboratory samples of blood, urine and tracheal aspirate are taken at the first day of life, day 3, day 7, day 14 and day 28 to evaluate laboratory markers for ventilator-induced lung injury and pulmonary hypertension.

DISCUSSION

To date, randomized clinical trials are lacking in the field of CDH. The VICI-trial, as the first randomized clinical trial in the field of CDH, may provide further insight in ventilation strategies in CDH patient. This may hopefully prevent mortality and morbidity.

TRIAL REGISTRATION

Netherlands Trial Register (NTR): NTR1310.

Prediction of chronic lung disease, survival and need for ECMO therapy in infants with congenital diaphragmatic hernia: additional value of fetal MRI measurements?

INTRODUCTION

The lung-to-head ratio (LHR), measured by ultrasound, and the fetal lung volume (FLV), measured by MRI, are both used to predict survival and need for extra corporeal membrane oxygenation (ECMO) in infants with congenital diaphragmatic hernia (CDH). The aim of this study is to determine whether MRI measurements of the FLV, in addition to standard ultrasound measurements of the LHR, give better prediction of chronic lung disease, mortality by day 28 and need for ECMO.

MATERIALS AND METHODS

Patients with unilateral isolated CDH born between January 2002 and December 2008 were eligible for inclusion. LHR and FLV were expressed as observed-to-expected values (O/E LHR and O/E FLV). Univariate and multivariate analyses were performed. Receiver operating characteristic curves were constructed and areas under the curve (AUC) were calculated to determine predictive values.

RESULTS

90 patients were included in the analysis. Combined measurement of the O/E LHR and O/E FLV gave a slightly better prediction of chronic lung disease (AUC=0.83 and AUC=0.87) and need for ECMO therapy (AUC=0.77 and AUC=0.81) than standard ultrasound measurements of the O/E LHR alone. Combined measurement of the O/E LHR and O/E FLV did not improve prediction of early mortality (AUC=0.90) compared to measurement of the O/E LHR alone (AUC=0.89). An intrathoracal position of the liver was independently associated with a higher risk of early mortality (p<0.001), chronic lung disease (p=0.007) and need for ECMO therapy (p=0.001).

DISCUSSION

Chronic lung disease and need for ECMO therapy are slightly better predicted by combined measurement of the O/E LHR and the O/E FLV. Early mortality is very well predicted by measurement of the O/E LHR alone.

CONCLUSION

Clinical relevance of additional MRI measurements may be debated.

[Congenital diaphragmatic hernia - mechanisms of pulmonary hypoplasia]

Congenital diaphragmatic hernia (CDH) is a common cause of severe neonatal respiratory distress. Mortality and morbidity are determined by the amount of pulmonary hypoplasia (PH) that occurs and by the development of therapy-resistant pulmonary hypertension. The pathogenesis and aetiology of CDH and its associated anomalies are still largely unknown despite all research efforts. The pathogenesis of CDH is based on an assumption linking herniation of abdominal viscera into the thorax with compression of the developing lung. PH, however, can also result from reduced distension of the developing lung secondary to impaired fetal breathing movements. Our understanding of CDH has also been aided by basic research with the use of dietary, teratogen-induced, and knockout models of CDH. These studies indicate that lung hypoplasia may involve disturbances of mitogenic signalling pathways fundamental to embryonic lung development. Recent data reveal the role of disruption of a retinoid-signalling pathway in the pathogenesis of CDH. Although multifactorial inheritance may best explain most cases of CDH in humans, much has been learned about the genetic factors that play a role in the development of CDH by studies of patients with CDH caused by specific genetic syndromes and chromosome anomalies. More research is warranted to improve our understanding of normal and abnormal lung development in relation to CDH. Such investigations will help in the design of new treatment strategies to improve the natural course or even to prevent this anomaly.

Regulation of the Pulmonary Circulation in the Fetus and Newborn

During the development of the pulmonary vasculature in the fetus, many structural and functional changes occur to prepare the lung for the transition to air breathing. The development of the pulmonary circulation is genetically controlled by an array of mitogenic factors in a temporo-spatial order. With advancing gestation, pulmonary vessels acquire increased vasoreactivity. The fetal pulmonary vasculature is exposed to a low oxygen tension environment that promotes high intrinsic myogenic tone and high vasocontractility. At birth, a dramatic reduction in pulmonary arterial pressure and resistance occurs with an increase in oxygen tension and blood flow. The striking hemodynamic differences in the pulmonary circulation of the fetus and newborn are regulated by various factors and vasoactive agents. Among them, nitric oxide, endothelin-1, and prostaglandin I2 are mainly derived from endothelial cells and exert their effects via cGMP, cAMP, and Rho kinase signaling pathways. Alterations in these signaling pathways may lead to vascular remodeling, high vasocontractility, and persistent pulmonary hypertension of the newborn.

Nitrofen induces apoptosis independently of retinaldehyde dehydrogenase (RALDH) inhibition

BACKGROUND

Nitrofen is a diphenyl ether that induces congenital diaphragmatic hernia (CDH) in rodents. Its mechanism of action has been hypothesized as inhibition of the retinaldehyde dehydrogenase (RALDH) enzymes with consequent reduced retinoic acid signaling.

METHODS

To determine if nitrofen inhibits RALDH enzymes, a reporter gene construct containing a retinoic acid response-element (RARE) was transfected into HEK-293 cells and treated with varying concentrations of nitrofen in the presence of retinaldehyde (retinal). Cell death was characterized by caspace-cleavage microplate assays and terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assays. Ex vivo analyses of cell viability were characterized in fetal rat lung explants using Live/Dead staining. Cell proliferation and apoptosis were assessed using fluorescent immunohistochemistry with phosphorylated histone and activated caspase antibodies on explant tissues. Nile red staining was used to identify intracellular lipid droplets.

RESULTS

Nitrofen-induced dose-dependent declines in RARE-reporter gene expression. However, similar reductions were observed in control-reporter constructs suggesting that nitrofen compromised cell viability. These observed declines in cell viability resulted from increased cell death and were confirmed using two independent assays. Ex vivo analyses showed that mesenchymal cells were particularly susceptible to nitrofen-induced apoptosis while epithelial cell proliferation was dramatically reduced in fetal rat lung explants. Nitrofen treatment of these explants also showed profound lipid redistribution, primarily to phagocytes.

CONCLUSIONS

The observed declines in nitrofen-associated retinoic acid signaling appear to be independent of RALDH inhibition and likely result from nitrofen induced cell death/apoptosis. These results support a cellular apoptotic mechanism of CDH development, independent of RALDH inhibition.

Maternal periconceptional exposure to cigarette smoking and alcohol consumption and congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a major birth defect that occurs when abdominal organs herniate through a diaphragmatic opening into the thoracic cavity and is associated with high mortality (>50%). The etiology of CDH is not well understood.

METHODS

Using data from the National Birth Defects Prevention Study, we examined associations between CDH and maternal periconceptional exposure (1 month before through the third month of pregnancy) to cigarette smoking and alcohol. Interview reports of exposures were provided by mothers of CDH (n = 503) and unaffected control (n = 6703) infants delivered from October 1997 through December 2005. Any exposure (yes/no), as well as quantity (average number of cigarettes or drinks), type (active/passive smoking; beer, wine, distilled spirits), and duration (e.g., number of months exposed) were examined. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated for all CDH cases combined, selected subtypes (Bochdalek, Morgagni, not otherwise specified), and phenotypes (infants with/without additional major birth defects).

RESULTS

The aOR for any smoking was nonsignificantly elevated for all CDH cases combined. Odds of any smoking was significant for isolated Bochdalek CDH (aOR, 1.9; 95% CI, 1.2-3.0). The aORs associated with all measures of alcohol consumption were near unity for each CDH category examined. Stratification of smoking exposure by alcohol consumption and stratification of alcohol consumption by smoking exposure did not appreciably change the aORs.

CONCLUSIONS

These findings identified periconceptional smoking exposure as a potential risk factor for CDH. Future studies need to confirm our findings and explore possible pathways accounting for the teratogenic effect of smoking.

A maternally inherited chromosome 18q22.1 deletion in a male with late-presenting diaphragmatic hernia and microphthalmia-evaluation of DSEL as a candidate gene for the diaphragmatic defect

Using an Affymetrix GeneChip(R) Human Mapping 100K Set to study a patient with a late-presenting, right-sided diaphragmatic hernia and microphthalmia, we found a maternally inherited deletion that was 2.7 Mb in size at chromosome 18q22.1. Mapping of this deletion using fluorescence in situ hybridization revealed three deleted genes-CDH19, DSEL, and TXNDC10, and one gene that contained the deletion breakpoint, CCDC102B. We selected DSEL for further study in 125 patients with diaphragmatic hernias, as it is involved in the synthesis of decorin, a protein that is required for normal collagen formation and that is upregulated during myogenesis. We found p.Met14Ile in an unrelated patient with a late-presenting, anterior diaphragmatic hernia. In the murine diaphragm, Dsel was only weakly expressed at the time of diaphragm closure and its expression in C2C12 myoblast cells did not change significantly during myoblast differentiation, thus reducing the likelihood that the gene is involved in myogenesis of the diaphragm. Although it is possible that the 18q22.1 deletion and haploinsufficiency for DSEL contributed to the diaphragmatic defect in the patient, a definite role for DSEL and decorin in the formation of the collagen-containing, central tendon of the diaphragm has not yet been established.

Insulinlike growth factor receptor type 1 and type 2 are downregulated in the nitrofen-induced hypoplastic lung

PURPOSE

In congenital diaphragmatic hernia (CDH), high mortality rates are attributed to severe pulmonary hypoplasia. The insulinlike growth factor receptor type 1 (IGF-1R) and type 2 (IGF-2R) play a critical role in the alveologenesis during lung development. The IGF-1R null mutation mice die after birth because of respiratory failure. The IGF-2R knockout mice showed retarded lungs with poorly formed alveoli. We hypothesized that IGF-1R and IGF-2R gene expression levels are downregulated in the nitrofen-induced CDH model.

METHODS

Pregnant rats were exposed to either olive oil or 100 mg of nitrofen on day 9.5 (D9.5) of gestation. Fetuses were harvested on D18 and D21 and divided into control and nitrofen groups. Relative messenger RNA (mRNA) levels of IGF-1R and IGF-2R were determined using real time reverse transcription polymerase chain reaction. Immunohistochemistry was performed to determine protein expression.

RESULTS

Relative levels of IGF-1R mRNA were significantly decreased in the nitrofen group (2.91 +/- 0.81) on D21 compared to controls (5.29 +/- 2.59) (P < .05). Expression levels of IGF-2R mRNA on D21 were also significantly decreased in nitrofen group (1.76 +/- 0.49) compared to controls (3.59 +/- 2.45) (P < .05). Immunohistochemistry performed on D21 showed decreased IGF-1R and also IGF-2R expression in nitrofen group.

CONCLUSION

Downregulation of IGF-1R and IGF-2R gene expression may interfere with normal alveologenesis causing pulmonary hypoplasia in the nitrofen-induced CDH model.

Spatiotemporal alteration in phosphatidylinositide 3-kinase-serine/threonine protein kinase B signaling in the nitrofen-induced hypoplastic lung

PURPOSE

The pathogenesis of pulmonary hypoplasia in congenital diaphragmatic hernia (CDH) is not fully understood. The serine/threonine protein kinase B (AKT) plays important roles for lung morphogenesis through epithelial-mesenchymal interaction in phosphatidylinositide 3-kinase (PI3K)-dependent manner. It has been reported that the lung explant morphogenesis in mice is interfered by inhibitors of the PI3K-AKT pathway. We hypothesized that PI3K and AKT gene and protein expression/distribution are altered during epithelial morphogenesis in the nitrofen-induced hypoplastic lung.

METHODS

Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal lungs were harvested on D15, D18, and D21 and divided into 3 groups as follows: control, nitrofen with CDH (CDH[-]), and nitrofen without CDH (CDH[+]) (n = 8 at each time-point, respectively). Reverse transcription polymerase chain reaction and immunohistochemistry were performed.

RESULTS

Messenger RNA expression levels of PI3K at D21 was significantly decreased in CDH(-) and CDH(+) group (5.71 +/- 0.85 and 6.80 +/- 0.88, respectively) compared to controls (8.95 +/- 3.22; P < .05). Messenger RNA levels of AKT were also significantly decreased at D18 in CDH(-) and CDH(+) lungs (1.21 +/- 0.16 and 1.20 +/- 0.32, respectively) compared to controls (1.62 +/- 0.14; P < .01). The PI3K immunoreactivity was diminished in the distal epithelium at D18 and decreased in the overall intensity at D21 in hypoplastic lungs compared to controls. The AKT immunoreactivity was decreased in mesenchyme at D18 and decreased overall intensity at D21 in CDH lungs compared to controls.

CONCLUSION

Spatiotemporal alteration of pulmonary PI3K and AKT gene and protein expression during epithelial morphogenesis may interfere with epithelial-mesenchymal interaction, causing pulmonary hypoplasia in CDH by disrupting PI3K-AKT signaling pathway.

Changing perspectives on the perinatal management of isolated congenital diaphragmatic hernia in Europe

Congenital diaphragmatic hernia (CDH) should be diagnosed in the prenatal period and prompt referral to a tertiary referral center for imaging, genetic testing, and multidisciplinary counseling. Individual prediction of prognosis is based on the absence of additional anomalies, lung size, and liver herniation. In severe cases, a prenatal endotracheal balloon procedure is currently being offered at specialized centers. Fetal intervention is now also offered to milder cases within a trial, hypothesizing that this may reduce the occurrence of bronchopulmonary dysplasia in survivors. Postnatal management has been standardized by European high-volume centers for the purpose of this and other trials.

A pediatric surgeon retools in genetics and genomics to study congenital diaphragmatic hernia

Prof. Donahoe outlines her career-long interest in congenital diaphragmatic hernia and how this has led to her current investigations into its etiology and possible treatment using gene probes.

Timing of delivery and survival rates for infants with prenatal diagnoses of congenital diaphragmatic hernia

OBJECTIVES

The goal of the study was to test the hypothesis that infants with known congenital diaphragmatic hernias born at early term gestation (37-38 weeks) rather than later (39-41 weeks) had greater survival rates and less extracorporeal membrane oxygenation use. Primary outcomes were survival to hospital discharge or transfer and extracorporeal membrane oxygenation use. METHODS; A retrospective cohort study of term infants with prenatal diagnoses of congenital diaphragmatic hernia was performed with the Congenital Diaphragmatic Hernia Study Group Registry of patients with congenital diaphragmatic hernias who were treated between January 1995 and December 2006.

RESULTS

Among 628 term infants at 37 to 41 weeks of gestation who had prenatal diagnoses of congenital diaphragmatic hernia and were free of major associated anomalies, early term birth (37 vs 39-41 weeks) and greater birth weight were associated independently with survival, whereas black race was related inversely to survival. Infants born at early term with birth weights at or above the group mean (3.1 kg) had the greatest survival rate (80%). Among infants born through elective cesarean delivery, infants born at 37 to 38 weeks of gestation, compared with 39 to 41 weeks, had less use of extracorporeal membrane oxygenation (22.0% vs 35.5%) and a trend toward a greater survival rate (75.0% vs 65.8%).

CONCLUSIONS

The timing of delivery is an independent, potentially important factor in the consideration of elective delivery for infants diagnosed prenatally as having congenital diaphragmatic hernias. Among fetuses with prenatally diagnosed congenital diaphragmatic hernias and without major associated anomalies, early term delivery may confer advantage.

Antenatal prediction of lung volume and in-utero treatment by fetal endoscopic tracheal occlusion in severe isolated congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a severe malformation with an overall survival between 30% and 90%. Survival in the presence of associated malformations is very low. The condition should be detected in ultrasound screening programmes, but whether and how prenatal imaging can accurately predict outcome remains a matter of debate. Predictions based on the lung area:head circumference ratio and liver position are best studied. This information is highly relevant in counselling patients, leaving to severe cases the option of termination of pregnancy as experimental prenatal intervention aiming to reverse pulmonary hypoplasia. The purpose of this review is to update current knowledge regarding predictive value of prenatal assessment in terms of neonatal survival. We will also discuss experimental evidence and clinical data regarding fetal tracheal occlusion.

Prenatal diagnosis, prediction of outcome and in utero therapy of isolated congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) can be associated with genetic or structural anomalies with poor prognosis. In isolated cases, survival is dependent on the degree of lung hypoplasia and liver position. Cases should be referred in utero to tertiary care centers familiar with this condition both for prediction of outcome as well as timed delivery. The best validated prognostic indicator is the lung area to head circumference ratio. Ultrasound is used to measure the lung area of the index case, which is then expressed as a proportion of what is expected normally (observed/expected LHR). When O/E LHR is < 25% survival chances are < 15%. Prenatal intervention, aiming to stimulate lung growth, can be achieved by temporary fetal endoscopic tracheal occlusion (FETO). A balloon is percutaneously inserted into the trachea at 26-28 weeks, and reversal of occlusion is planned at 34 weeks. Growing experience has demonstrated the feasibility and safety of the technique with a survival rate of about 50%. The lung response to, and outcome after FETO, is dependent on pre-existing lung size as well gestational age at birth. Early data show that FETO does not increase morbidity in survivors, when compared to historical controls. Several trials are currently under design.

Management of congenital diaphragmatic hernia

PURPOSE OF REVIEW

To evaluate the impact of recent research on the management of congenital diaphragmatic hernia in the light of new theories on embryological development, earlier antenatal diagnosis, fetal and postnatal interventions together with advances in perinatal intensive care.

RECENT FINDINGS

The year 2007 provided in excess of 200 publications that address various aspects of congenital diaphragmatic hernia. The genetic basis and the causes of pulmonary hypoplasia at the molecular level are slowly being unravelled. Fetal MRI of lung volume, lung-head ratio, liver position and size of diaphragmatic defect have all been evaluated as early predictors of outcome and with a view to prenatal counselling. The impact of fetal interventions such as fetal endoluminal tracheal occlusion, the mode of delivery, the surgical techniques and agents for treating pulmonary hypertension were evaluated. The influence of associated anomalies and therapeutic interventions on the outcome and quality of life of survivors continue to be appraised.

SUMMARY

Deferred surgery after stabilization with gentle ventilation and reversal of pulmonary hypertension remain the cornerstones of management. Optimal presurgery and postsurgery ventilatory settings remain unproven. Continued improvement in neonatal intensive care raises the bar against which any intervention such as fetal endoluminal tracheal occlusion and extracorporeal membrane oxygenation will be judged.

Genetic aspects of human congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common major malformation affecting 1/3000-1/4000 births, which continues to be associated with significant perinatal mortality. Much current research is focused on elucidating the genetics and pathophysiology contributing to CDH to develop more effective therapies. The latest data suggest that many cases of CDH are genetically determined and also indicate that CDH is etiologically heterogeneous. The present review will provide a brief summary of diaphragm development and model organism work most relevant to human CDH and will primarily describe important human phenotypes associated with CDH and also provide recommendations for diagnostic evaluation of a fetus or infant with CDH.