Fetoscopic Surgery as Prenatal Intervention for Isolated Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) occurs sporadically with an incidence of 1:2500 live births. Despite the progress in neonatal intensive care, CDH remains associated with a mortality of at least 30% in isolated cases. The in essence surgically correctable defect of the diaphragm enables the prenatal herniation of abdominal organs into the thoracic cavity. The resulting abnormal development of the airways and pulmonary vessels causes neonatal respiratory insufficiency and persistent pulmonary hypertension. The condition can be diagnosed prenatally and the degree of pulmonary hypoplasia, which determines the postnatal course, can be measured to make an individual prognosis. In severely affected patients, prenatal surgery may improve neonatal outcome by reversing Pulmonary hypoplasia. This is currently implemented by percutaneous fetoscopic endoluminal tracheal occlusion (FETO) to trigger fetal lung growth. Although there are no maternal complications, preterm rupture of the membranes remains the major drawback of the procedure (20% < 34weeks). However, as compared to historical controls of a similar severity, Survival as well as early neonatal morbidity are significantly improved by FETO. As a consequence, a multicentre randomised-controlled trial in fetuses with moderate hypoplasia on FETO compared to expectant management has been started (www.totaltrial.eu). Primary outcome measure is Survival without chronic lung disease (i.e., without bronchopulmonary dysplasia). A trial in severely affected fetuses with survival as main outcome is currently under review by ethics committee. A standardised neonatal management enables optimal treatment and multicentre compatibility. It remains to be proven if fetoscopic surgery can maintain a solid position in the prenatal treatment of CDH to improve both mortality and morbidity of the affected children.