Fetoscopic Endoluminal Tracheal Occlusion

Despite advances in prenatal diagnosis and postnatal therapies, including extracorporeal membrane oxygenation (ECMO), inhaled nitric oxide therapy, and ventilator strategies that minimize ventilator-induced lung injury, morbidity and mortality rates for babies with severe CDH remain high. Data from Children's Hospital of Philadelphia (CHOP) between January 2006 and December 2010 for prenatal and postnatal care for 64 patients with isolated left CDH showed overall survival was 63%. Survival was 33% in patients requiring the use ECMO. Immediate morbidity/mortality is related to the severity of the pulmonary hypoplasia caused by the mass effect of the herniated abdominal contents on the developing lungs. Quantifying the severity of pulmonary hypoplasia has been performed using the observed/expected lung to head circumference ratio (O/E LHR). It is a tool validated in 354 fetuses with unilateral isolated CDH evaluated between 18 and 38 weeks gestation. For O/E LHR \< 25%, survival was dismal at 1/9 or 11% (CHOP experience, not published). Published data from an interdisciplinary follow-up program at CHOP shows striking morbidities in neuromuscular tone and neurodevelopmental status. The rationale for fetal therapy in severe CDH is to improve fetal lung growth and therefore neonatal survival. Prenatal tracheal occlusion obstructs the normal egress of lung fluid during pulmonary development leading to increased lung tissue stretch, increased cell proliferation, and accelerated lung growth. European colleagues have developed foregut endoscopy and techniques to position and remove endoluminal tracheal balloons in utero. Recently, the Belgium group published summary results of FETO showing an improved survival in 175 patients with isolated left CDH from 24% to 49%. The investigators goal with this pilot study is to study the feasibility of implementing FETO therapy in the most severe group of fetuses with left CDH (O/E\< 25%; O/E \< 30%) and right CDH (O/E \< 45%).