Phase 2 Fetal Tracheal Balloon (IDE G080077) Study in Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) has traditionally been associated with very high mortality rates. Most infants died of pulmonary hypoplasia and severe pulmonary hypertension. This led to correction of CDH and pulmonary hypoplasia before birth. Unfortunately, maternal morbidity of open fetal surgery was significant and fetal mortality was very high (>60%). Moreover, the results of postnatal therapy for CDH improved dramatically, from less than 20% survival several decades ago to more than 70% today.

Fetal intervention has evolved as well, to a minimally invasive approach that involves a single endoscopic port and occlusion of the fetal trachea. While this has considerably decreased the morbidity and fetal mortality of the in utero procedure, its results do not exceed the overall (i.e., non-stratified) results of contemporary postnatal treatment. Most recently, a multicentric cooperative study under (Eurofoetus) has conducted a clinical trial comparing postnatal treatment with endoscopic fetal tracheal occlusion for the most severe forms of CDH. Results of the Eurofoetus trial and of a recent retrospective review involving European and North-American centers have shown the following: 1) It is possible to identify a specific subgroup of fetuses with CDH in whom survival can be predicted to be less than 10%, despite all current methods of postnatal treatment, 2) Survival of fetuses with predicted postnatal survival of 8% was >50% following endoscopic fetal tracheal occlusion, and 3) Fetal tracheal occlusion in that group resulted in an increase in lung size (LHR), from an average of 0.7 pre-intervention, to 1.7 post-intervention.

Based on the available research literature, the results of the Eurofoetus trial, and this institution's experience with endoscopic fetal surgery, we hypothesize that in the highest risk group of fetuses with congenital diaphragmatic hernia, where chances of survival is estimated at less than 10%, endoscopic fetal tracheal occlusion in late second trimester, with reversal of occlusion in mid-third trimester, allows catch-up lung growth and maturation and converts the condition into one with intermediate to good prognosis (predicted survival 50-60%). We propose to offer this form of treatment, under an FDA-approved Investigational Device Exemption (G080077), to eligible patients, on a case-by-case basis, after discussion before a multidisciplinary board.