Fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia: indications, outcomes, and future directions

In the present study, we review the indications, technical aspects, preliminary results, risks, and clinical implications of fetal endoscopic tracheal occlusion (FETO) for severe congenital diaphragmatic hernia (CDH) performed outside the United States and its potential future directions in this country and globally. Congenital diaphragmatic hernia occurs in approximately 1 in 2500 live births and results in high neonatal morbidity and mortality, largely associated with the severity of pulmonary hypoplasia and pulmonary arterial hypertension. With the advent of prenatal imaging, CDH can be diagnosed before birth, and in utero treatment is now available in some centers. The prognosis of CDH can be evaluated by assessing the fetal lung size, the degree of liver herniation, and the fetal pulmonary vasculature in isolated forms of CDH. These parameters help classify fetuses as having mild, moderate, severe, or extremely severe isolated CDH. Severe and extremely severe diaphragmatic hernias have poor outcomes and thus are candidates for innovative therapies such as FETO. Fetal endoscopic tracheal occlusion is usually performed between 26 and 30 weeks' gestation. In utero, an endoscope is passed through the fetal mouth and down to the carina; the balloon is deployed just above the carina. After the procedure, ultrasound surveillance every 2 weeks ensures the balloon's structural integrity and measures the fetal pulmonary response. At approximately 34 weeks' gestation, the balloon is deflated and removed. Fetal endoscopic tracheal occlusion is thought to improve outcomes by decreasing mortality and allowing more rapid neonatal stabilization. Ultimately, the goal of FETO is to minimize pulmonary hypoplasia and pulmonary arterial hypertension. Following delivery, neonates still require diaphragm repair.