Congenital Diaphragmatic Hernia

Despite progress in prenatal diagnosis and postnatal therapy, congenital diaphragmatic hernia (CDH) still carries a significant mortality and considerable short- and long-term morbidity. Further clinical improvement could be accomplished by standardising care in an international setting and harmonising complication registration in a collective database such as the CDH registry. Therefore, the foundation of the European CDH consortium and the international CDH study group should be heartily welcomed.

In addition, research efforts are directed at the very early embryonic processes, the antenatal history of CDH, and factors that lead to CDH. Despite the increased knowledge on the genesis of CDH with abnormal development of the diaphragm and the abnormalities in the lung and pulmonary vasculature, we are still left with a large black box in the natural history of CDH that determines the difference in postnatal clinical course. More knowledge on these issues could lead to new treatment modalities (especially for pulmonary hypertension) and perhaps even prevention strategies. New trends in this field concern regenerative medicine, originally focused on development of new patches, but the real step forward will probably be stem-cell techniques and prenatal therapy.

CDH is characterized by a wide spectrum of clinical presentations. Patients generally can be distinguished into three main groups in terms of outcome. The first group (mild) consists of infants born with a diaphragmatic defect who suffer no or mild respiratory insufficiency and have no signs of pulmonary hypertension on cardiac ultrasound. Those infants will survive almost without any morbidity. In the second group (moderate), infants suffer respiratory insufficiency and have clinical signs of pulmonary hypertension, confirmed with cardiac ultrasound. A certain proportion of these infants will survive, but will suffer pulmonary morbidity and/or neurodevelopmental disabilities; the others will die as result of iatrogenesis. In the latter, an inflammatory response, as a consequence of and in combination with ventilation-induced injury, triggers the development of bronchopulmonary dysplasia, or chronic neonatal lung disease, which is also associated with pulmonary hypertension. The ongoing respiratory insufficiency will result in the development of a fixed pulmonary hypertension that is eventually no longer responding to the currently used but largely non-evidence-based therapeutic approaches. The third group (severe) consists of those who suffer severe respiratory insufficiency and pulmonary hypertension and do not show any hemodynamic improvement with the current therapeutic approaches including extracorporeal membrane oxygenation. These are the so-called non-responders, who will not survive. Predicting the outcome group for the individual patient remains one of the major challenges. Concerning the surgical treatment modalities, the introduction of minimal access surgery and the use of biodegradable patches have been widely introduced in some leading but also in some low volume centres during the last decade. Both techniques are still under debate concerning their outcome.

In this issue of the European Journal of Pediatric Surgery we reviewed the developments of the past 5 years and future perspectives concerning the etiology, the pulmonary and surgical interventions, and the long-term outcome. As CDH is a rare congenital malformation with multiple clinical aspects, research has to help us solve the problems in larger consortiums. Therefore the European CDH consortium organizes the international CDH symposium every second year. The upcoming symposium will be held on June 9–10, 2013 in Rotterdam, directly after the EUPSA meeting and before the ESPNIC, which is the ideal time to join the surgeons and neonatologists and intensive care pediatricians in this field. We will welcome everybody interested in the new developments on CDH.