Fetoscopic Therapy for Severe Pulmonary Hypoplasia in Congenital Diaphragmatic Hernia: A First in Prenatal Regenerative Medicine at Mayo Clinic.

Objective: To introduce the prenatal regenerative medicine service at Mayo Clinic for fetal endoscopic tracheal occlusion (FETO) care for severe congenital diaphragmatic hernia (CDH).

Patients And Methods: Two cases of prenatal management of severe CDH with FETO between January and August 2017 are reported. Per protocol, FETO was offered for life-threatening severe CDH at between 26 and 29 weeks' gestation. Regenerative outcome end point was fetal lung growth. Gestational age at procedure and maternal and perinatal outcomes were additional monitored parameters.

Results: Diagnosis by ultrasonography of severe CDH was based on extremely reduced lung size (observed-to-expected lung area to head circumference ratio [o/e-LHR], eg, o/e-LHR of 20.3% for fetus 1 and 23.0% for fetus 2) along with greater than one-third of the liver herniated into the chest in both fetuses. Both patients underwent successful FETO at 28 weeks. At the time of intervention, no maternal or fetal complications were observed. Postintervention, fetal lung growth was observed in both fetuses, reaching an o/e-LHR of 62.7% at 36 weeks in fetus 1 and 52.4% at 32 weeks in fetus 2. The balloons were removed successfully at 35 weeks and 4 days by ultrasound-guided puncture in the first patient and at 32 weeks and 3 days by ex utero intrapartum therapy-to-airway procedure in the second patient. Postnatal management followed standard of care with patch CDH therapy. At discharge, one patient was breathing normally, whereas the other required minimal nasal cannula oxygen support.

Conclusion: The successful launch of the first fetoscopic therapy for CDH at Mayo Clinic reveals its feasibility and safety, with early signs of benefit documented by fetal lung growth and reversal of severe pulmonary hypoplasia.

Trial Registration: clinicaltrials.gov Identifier: G170062.