Congenital diaphragmatic hernia: focus on abnormal muscle formation

Impact of fetal treatments for congenital diaphragmatic hernia on lung development

The extent of lung hypoplasia impacts the survival and severity of morbidities associated with congenital diaphragmatic hernia (CDH). The alveoli of CDH infants and in experimental models of CDH have thickened septa with fewer type II pneumocytes and capillaries. Fetal treatments of CDH-risk preterm birth. Therefore, treatments must aim to balance the need for increased gas exchange surface area with the restoration of pulmonary epithelial type II cells and the long-term respiratory and neurodevelopmental consequences of prematurity. Achievement of sufficient lung development in utero for successful postnatal transition requires adequate intra-thoracic space for lung growth, maintenance of sufficient volume and appropriate composition of fetal lung fluid, regular fetal breathing movements, appropriate gas exchange area, and ample surfactant production. The review aims to examine the rationale for current and future therapeutic strategies to improve postnatal outcomes of infants with CDH.

Morphofunctional Characterization of Different Tissue Factors in Congenital Diaphragmatic Hernia Affected Tissue

Congenital diaphragm hernia (CDH) is a congenital disease that occurs during prenatal development. Although the morbidity and mortality rate is rather significant, the pathogenesis of CDH has been studied insignificantly due to the decreased accessibility of human pathological material. Therefore the aim of our work was to evaluate growth factors (transforming growth factor-beta (TGF-β), basic fibroblast growth factor (bFGF), insulin-like growth factor 1 (IGF-1), hepatocyte growth factor (HGF)) and their receptors (fibroblast growth factor receptor 1 (FGFR1), insulin-like growth factor 1 (IGF-1R)), muscle (dystrophin, myosin, alpha actin) and nerve quality (nerve growth factor (NGF), nerve growth factor receptor (NGFR), neurofilaments (NF)) factors, local defense factors (ß-defensin 2, ß-defensin 4), programmed cell death (TUNEL), and separate gene (Wnt-1) expression in human pathological material to find immunohistochemical marker differences between the control and the CDH patient groups. A semi-quantitative counting method was used for the evaluation of the tissues and structures in the Biotin-Streptavidin-stained slides. Various statistically significant differences were found in immunoreactive expression between the patient and the control group tissue and the morphological structures as well as very strong, strong, and moderate correlations between immunoreactives in different diaphragm cells and structures. These significant changes and various correlations indicate that multiple morphopathogenetic pathways are affected in CDH pathogenesis. This work contains the evaluation of the causes for these changes and their potential involvement in CDH pathogenesis.

Providing direction improves function: Comparison of a radial pore-orientated acellular collagen scaffold to clinical alternatives in a surgically induced rabbit diaphragmatic tissue defect model

Gore-Tex® is a widely used durable patch for repair of congenital diaphragmatic defects yet may result in complications. We compared Gore-Tex with a composite of a radial pore-orientated collagen scaffold (RP-Composite) and clinically used porcine small intestinal submucosa (SIS; Surgisis®) in a rabbit model for diaphragmatic hernia. The growing rabbit mimics the rapid rib cage growth and reherniation rates seen in children. We created and immediately repaired left hemidiaphragmatic defects in 6-week-old rabbits with Gore-Tex, SIS, and an RP-Composite scaffold. An additional group of rabbits had a sham operation. At 90 days, survivors more than doubled in weight. We observed few reherniations or eventrations in Gore-Tex (17%) and RP-Composite (22%) implanted animals. However, SIS failed in all rabbits. Maximum transdiaphragmatic pressure was lower in Gore-Tex (71%) than RP-Composite implanted animals (112%) or sham (134%). Gore-Tex repairs were less compliant than RP-Composite, which behaved as sham diaphragm (p < 0.01). RP-Composite induced less foreign body giant cell reaction than Gore-Tex (p < 0.05) with more collagen deposition (p < 0.001), although there was a tendency for the scaffold to calcify. Unlike Gore-Tex, the compliance of diaphragms reconstructed with RP-Composite scaffolds were comparable with native diaphragm, whereas reherniation rates and transdiaphragmatic pressure measurements were similar.

Regenerative medicine solutions in congenital diaphragmatic hernia

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

Congenital diaphragmatic hernia: endotracheal fluid phospholipidic profile following tracheal occlusion in an experimental model

OBJECTIVE

To compare endotracheal fluid (EF) and amniotic fluid (AF) phospholipidic profile changes following tracheal occlusion (TO) in the congenital diaphragmatic hernia (CDH) fetal lamb model, in order to support the efficacy of TO on lung maturity.

METHODS

A diaphragmatic defect was induced at 70 days' gestation, TO was carried out at day 102 and cesarean section at 136 days' gestation. EF and AF samples, collected at delivery, were evaluated using mass spectrometry (the analysis focused on palmitoyloleoyl-phosphatidylcholine [POPC, PC(18:1/16:0)], dipalmitoyl-phosphatidylcholine [DPPC, PC(16:0/16:0)] and sphingomyelins [SMs]).

RESULTS

The effects of CDH and TO were different on AF and EF. POPC levels were higher than DPPC levels in AF of healthy lambs. Following induction of the diaphragmatic malformation, an evident decrease in POPC was noted, while a substantial return to normal POPC levels and an increased DPPC peak were prompted by the TO. After CDH induction, a decrease in N-palmitoyl-D-sphingomyelin [SM(d18:1/16:0)] was revealed (P<0.01) and an increased peak in SMs in AF was prompted by the TO (P=0.05). While the most represented phosphatidylcholine (PC) species in EF of healthy lambs was DPPC, CDH induced a decrease in the DPPC peak and treatment with TO induced its partial recovery. SMs were detectable only in healthy EF samples.

CONCLUSION

The phospholipid recovery profile following TO suggests the potential role of this therapy in restoring processes involved in surfactant-mediated lung maturation, even though other interactions involved in AF turnover should be considered. Moreover, these metabolites could be used as biomarkers of fetal pulmonary development.

Cardiac Adaptation to Severe Congenital Diaphragmatic Hernia

OBJECTIVE

Prenatal heart adaptations to congenital diaphragmatic hernia (CDH) could help define postnatal outcome.

METHODS

We retrospectively analyzed post-mortem tissues from fetuses with severe CDH (n = 7). Histology and immunohistochemical distribution of desmin, muscle actin [HHF35], endothelin-1 [ET-1] and TGF-β were evaluated.

RESULTS

In the atrium, desmin, HHF35, ET-1, TGF-β were found expressed only in preterm CDH. Dishomogeneous ventricular distribution of cardiac growth factors were detected in term CDH. The cardiomyocyte nucleus/cytoplasmatic ratio in CDH was higher compared with controls (p = 0.01). Small intramyocardial artery density and vascular wall thickness was increased in CDH compared with controls (p = 0.03 and p < 0.01). In comparison with the ventricles, the interventricular septum showed a greater vessel density (p = 0.01) and a greater vascular wall thickness, particularly compared with the CDH right ventricle (p = 0.02).

CONCLUSION

Left ventricle immaturity seems to be a cardiac adaptive response of severe CDH in utero.