Can we improve outcome of congenital diaphragmatic hernia?

This review gives an overview of the disease spectrum of congenital diaphragmatic hernia (CDH). Etiological factors, prenatal predictors of survival, new treatment strategies and long-term morbidity are described. Early recognition of problems and improvement of treatment strategies in CDH patients may increase survival and prevent secondary morbidity. Multidisciplinary healthcare is necessary to improve healthcare for CDH patients. Absence of international therapy guidelines, lack of evidence of many therapeutic modalities and the relative low number of CDH patients calls for cooperation between centers with an expertise in the treatment of CDH patients. The international CDH Euro-Consortium is an example of such a collaborative network, which enhances exchange of knowledge, future research and development of treatment protocols

Morphologic changes and methodological issues in the rabbit experimental model for diaphragmatic hernia

Fetal lung development may be impaired by some congenital anomalies or in utero events. Animal models are used to understand the pathophysiology of these diseases and explore therapeutic strategies. Our group has an interest in the prenatal management of congenital diaphragmatic hernia (CDH). Isolated CDH remains associated with a 30% mortality because of lung hypoplasia and pulmonary hypertension. On day 23 of gestation (pseudoglandular stage) CDH was created in both ovarian-end fetuses (n=28) in 14 time-mated pregnant white rabbits (hybrid of Dendermonde and New-Zealand White). At term (day 30) all survived operated fetuses and size-matched controls were harvested. Fetuses/lungs were assigned randomly to formalin fixation either under pressure of 25 cm H2O (CDH25 n=5; CTR25 n=5) or without (0 cm H2O (CDH0 n=7; CTR0 n=7). Fetuses and lungs were first weighed, and then the lungs were processed for morphometry. Pulmonary development was evaluated by lung-to-body weight ratio (LBWR) and airway and vascular morphometry. Surgical induction of CDH does reduce the LBWR to hypoplastic levels. The contralateral lung weight is 81% of what is expected, whereas the ipsilateral lung is only 46% of the normal. This was accompagnied by a loss of conducting airway generations, precisely, terminal bronchioles (TB), which were surrounded by less alveoli. The ipsilateral CDH lung demonstrated a thickened media in the peripheral arteries as well. As a result, in the severely hypoplastic ipsilateral lung, an airway fixation pressure of 25 H2O has no significant effect on the morphometric indices. The contralateral lung has a normal amount of alveoli around a single TB, which also behave like alveoli of the normal lung, i.e. expand under pressure fixation. The present study on severely hypoplastic lungs that never respirated, shows that in contrast to normal lungs, the morphometric indices are not significantly influenced by a difference in fixation pressure. Increasing fixation pressure seems to expand the lung only when sufficient alveolated parenchyma is present