Towards an endoscopic intra-uterine treatment for congenital diaphragmatic hernia.

Congenital Diaphragmatic Hernia (CDH) is a simple defect in the diaphragm that however can lead to severe or lethal pulmonary hypoplasia. Fetuses with their liver herniating into the thorax and with a small lung volume as reflected by a lung-to-head ratio below < 1.0, have virtually no chance to survive despite most modern postnatal care. They are therefore theoretical candidates for in utero therapy. There is a large experimental basis supporting tracheal occlusion (TO) as a method to trigger lung growth, although the optimal time and duration of TO remains to be defined in humans. Animal studies have also shown that TO can be performed completely endoscopically, by means of in utero tracheoscopy and endoluminal balloon placement. TO was therefore applied by leading fetal surgery centers. Initial results with tracheal clipping via hysterotomy were discouraging, but more recently fetoscopic clipping was associated with a nearly 70% survival. The time has now come to achieve TO by means of percutaneous fetoscopic balloon plugging. This will make the intervention more acceptable in a European setting, where open fetal surgery never took off.