Fetal Endotracheal Occlusion (FETO) in Fetuses with Severe Congenital Diaphragmatic Hernia

The goal of this pilot trial is to learn more about the role of Fetal Endotracheal Occlusion (FETO) as an intervention in fetuses with severe congenital diaphragmatic hernia (CDH). The research team will investigate the feasibility and safety of the FETO procedure, as well as determine whether FETO can improve lung growth before birth, and survival after birth.

This study will enroll 10 pregnant participants to undergo the FETO procedure at a gestational age of 27 weeks 0 days to 29 weeks 6 days. The participant will be monitored for a few weeks, and then the FETO removal procedure will be performed ideally at 34 weeks 0 days to 34 weeks 6 days, but may be indicated earlier as determined by the Maternal Fetal care team. The pregnant participant and their baby will continue to be monitored during delivery and up until the child reaches 2 years of age.

The goal of this study is to learn more about the role of Fetal Endotracheal Occlusion (FETO) as an intervention in fetuses with isolated severe congenital diaphragmatic hernia (CDH). CDH is a condition in which the diaphragm fails to completely close, leaving a gap through which abdominal organs can herniate and slide into and out of the chest. In severe cases, abdominal organs move into the chest and stay there, putting pressure on the heart and lungs and potentially causing the disruption or deformation of these structures. Impaired development of the lungs can often lead to a condition known as pulmonary hypertension, a form of high blood pressure that damages the heart. Pulmonary hypoplasia and pulmonary hypertension can be lethal. Congenital diaphragmatic hernia (CDH) affects 1 in 2,200 to 5,000 live births per year.

FETO will be performed with the goal of promoting lung growth and improving neonatal outcomes. FETO is a minimally invasive procedure in which a balloon device is inserted into the trachea of the fetus. The devices involved are the Goldballoon Detachable Balloon (GOLDBAL2) along with the Delivery Microcatheter (BALTACCI-BDPE100). The balloon would be left in place for several weeks and allow the lungs to grow, after which it would be removed, enabling the lungs to mature before birth. Participants will continue to be monitored up until the child reaches 2 years of age in order to assess mental and physical development after FETO.

Eligibility Criteria:
Inclusion Criteria:

* Pregnant patient 18 and older who is able to consent
* Singleton pregnancy
* Ability to reside within 30 minutes of Boston Children's Hospital for the duration of the FETO intervention, from the time of balloon placement until balloon removal
* Patient has a support person who is able to stay with them for the duration of the pregnancy

Fetal:

* Reassuring genetic analysis demonstrated by either normal Karyotype, normal fluorescence in situ hybridization (FISH) for chromosomes 13, 18, 21, X and Y, or chromosomal microarray (CMA) with non-pathologic variants
* Diagnosis of isolated left CDH with liver up
* Gestation at enrollment prior to 29 weeks 5 days
* SEVERE pulmonary hypoplasia with ultrasound Observed/Expected Lung-to-Head Ratio (O/E LHR) \< 25%

Exclusion Criteria:

* Maternal contraindication to fetoscopic surgery or severe maternal medical condition in pregnancy
* Technical limitations precluding fetoscopic surgery, including uterine anomaly such as large or multiple fibroids, or Mullerian duct anomaly
* Latex allergy
* Preterm labor, shortened cervix (\<20mm at enrollment or within 24 hours of FETO balloon insertion procedure) or uterine anomaly strongly predisposing to preterm labor, placenta previa
* Severe maternal obesity pre-pregnancy (BMI \> 40)
* Psychosocial ineligibility, precluding consent, as determined by clinic social worker during review
* Inability to remain at FETO site during time period of tracheal occlusion, delivery, and postnatal care
* Right-sided or bilateral, left-sided CDH observed-to-expected lung to head ratio \> 25% on ultrasound
* Additional fetal anomaly and chromosomal abnormalities by ultrasound, MRI, or echocardiogram that will significantly worsen prognosis
* History of incompetent cervix with or without cerclage
* Placental abnormalities (previa, abruption, accreta) known at time of enrollment
* Maternal-fetal RH (rhesus) isoimmunization, Kell sensitization, or neonatal alloimmune thrombocytopenia affecting the current pregnancy
* Maternal HIV, Hepatitis B, Hepatitis C status positive