Fetal Endotracheal Occlusion (FETO) in Severe Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) occurs when the diaphragm fails to fully fuse and leaves a portal through which abdominal structures can migrate into the thorax. In the more severe cases, the abdominal structures remain in the thoracic cavity and compromise the development of the lungs. Infants born with this defect have a decreased capacity for gas exchange; mortality rates after birth have been reported between 40-60%. Now that CDH can be accurately diagnosed by mid-gestation, a number of strategies have been developed to repair the hernia and promote lung tissue development.

Fetal tracheal occlusion is one technique that temporarily closes the herniated area with the Goldvalve balloon to allow the lungs to develop and increase survival at birth. This is a pilot study of a cohort of fetuses affected by severe CDH that will undergo FETO to demonstrate the feasibility of performing the procedure, managing the pregnancy during the period of tracheal occlusion, and removal of the device prior to delivery at BCM/Texas Children's Hospital (TCH). It is anticipated that fetal tracheal occlusion plug-unplug procedure will improve mortality and morbidity outcomes as compared with current management, but this is not a primary endpoint of the feasibility study. We will perform 15 FETO procedures on fetuses diagnosed prenatally with severe CDH.

Enrollment

Women carrying fetuses with left-sided CDH and a normal karyotype will undergo evaluation. The fetuses will be 22+0/7 to 29+6/7 weeks of gestational age. They will have ultrasound and/or MRI evaluation to rule out other anomalies, calculation of the LHR from ultrasound measurements, echocardiography, and detailed obstetric/perinatal consultation. Patients who meet the eligibility criteria will be extensively counseled, and those who wish to participate will provide written, informed consent for the study.

Procedure

The procedure will be performed under spinal anesthesia or local anesthesia with intravenous sedation. The technique of fetal endoscopic tracheal occlusion has been described. Using standard technique, a cannula loaded with a pyramidal trocar will be inserted into the amniotic cavity and a fetoscope or flexible operating endoscope will be passed through the cannula into the amniotic fluid. The scope will be guided into the fetal larynx either through a nostril and then via the nasal passage or through the fetal mouth, and then through the fetal vocal cords with the aid of both direct vision through the scope and cross-sectional ultrasonographic visualization. A detachable latex balloon will be placed in the fetal trachea midway between the carina and the vocal cords. The balloon will be inflated with isosmotic contrast material so that it fills the fetal trachea.

Postoperative

The mothers will be discharged once stable. Serial measurements of sonographic lung volume and LHR will begin within 24-48 hours following surgery and continue weekly by targeted ultrasound evaluation. Amniotic fluid level and membrane status will also be monitored at weekly intervals. Comprehensive ultrasonography for fetal growth will be performed every four weeks. All discharged patients will stay within 30 minutes of TCH to permit standardized postoperative management and emergent retrieval of the balloon in the event of preterm labor or premature rupture of membranes prior to the scheduled removal.

Balloon retrieval will be planned at between 32+0/7 and 34+6/7 weeks at the discretion of the FETO center.

After removal of the balloon, patients will have the choice of delivering at Texas Children's Hospital Pavilion for Women with the CDH managed and repaired at TCH, or returning to their obstetrician for delivery with subsequent repair of the CDH by the pediatric surgeons at their referring facility. Given the severity of the CDH, the baby will need to be delivered in a facility that has the capability of immediate pediatric surgery services.

Women ages 18 - 45 years old with a fetus that has a diagnosed CDH that fits the criteria are eligible. All ethnicities are eligible.

• Deprest J, Jani J, Gratacos E, Vandecruys H, Naulaers G, Delgado J, Greenough A, Nicolaides K; FETO Task Group. Fetal intervention for congenital diaphragmatic hernia: the European experience. Semin Perinatol. 2005 Apr;29(2):94-103. Review.
• Deprest J, Jani J, Van Schoubroeck D, Cannie M, Gallot D, Dymarkowski S, Fryns JP, Naulaers G, Gratacos E, Nicolaides K. Current consequences of prenatal diagnosis of congenital diaphragmatic hernia. J Pediatr Surg. 2006 Feb;41(2):423-30. Review.
• Doné E, Gucciardo L, Van Mieghem T, Jani J, Cannie M, Van Schoubroeck D, Devlieger R, Catte LD, Klaritsch P, Mayer S, Beck V, Debeer A, Gratacos E, Nicolaides K, Deprest J. Prenatal diagnosis, prediction of outcome and in utero therapy of isolated congenital diaphragmatic hernia. Prenat Diagn. 2008 Jul;28(7):581-91.
• Saura L, Castañón M, Prat J, Albert A, Caceres F, Moreno J, Gratacós E. Impact of fetal intervention on postnatal management of congenital diaphragmatic hernia. Eur J Pediatr Surg. 2007 Dec;17(6):404-7.
• Deprest JA, Hyett JA, Flake AW, Nicolaides K, Gratacos E. Current controversies in prenatal diagnosis 4: Should fetal surgery be done in all cases of severe diaphragmatic hernia? Prenat Diagn. 2009 Jan;29(1):15-9. No abstract available.
• Kohl T, Gembruch U, Tchatcheva K, Schaible T. Current consequences of prenatal diagnosis of congenital diaphragmatic hernia by Deprest et al (J Ped Surg 2006;41:423-30). J Pediatr Surg. 2006 Jul;41(7):1344-5; author reply 1345-6. No abstract available.
• Harrison MR, Adzick NS, Estes JM, Howell LJ. A prospective study of the outcome for fetuses with diaphragmatic hernia. JAMA. 1994 Feb 2;271(5):382-4.

Inclusion Criteria:

• Patient is a pregnant woman between 18 and 45 years of age
• Patient is able to give informed consent
• Normal fetal echocardiogram
• Normal fetal karyotype
• No evidence of other major fetal anomalies on ultrasound or MRI
• Confirmed diagnosis of CDH of the fetus
• Fetal liver herniated into the left hemithorax
• LHR is 1.0 or less, calculated between 22+0/7 weeks and 29+6/7 weeks of gestation
• Fetus is between 22+0/7 and 29+6/7 weeks of gestation at time of surgery
• Singleton pregnancy
• The mother must be healthy enough to have surgery and she must fully understand and accept the maternal and fetal risks involved
• Patient is willing to remain in Houston throughout the duration of balloon placement

Exclusion Criteria:

• Failure to meet all inclusion criteria
• Allergy to latex
• Known allergy or previous adverse reaction to a study medication specified in this protocol
• Contraindication to abdominal surgery, fetoscopic surgery, or general anesthesia
• Preterm labor, preeclampsia, or uterine anomaly (e.g., large fibroid tumor)
• Fetal aneuploidy, known structural genomic variants, or known syndromic mutation

• Baylor College of Medicine
• Texas Children's Hospital