Fetal Surgery for CDH: Fetoscopic Endoluminal Tracheal Occlusion (FETO)

Fetal Surgery for Congenital Diaphragmatic Hernia

Julie Moldenhauer, MD: Congenital diaphragmatic hernia is a very severe birth defect in which there is a hole in the forming diaphragm. And that then allows the contents of the abdomen, like the bowel and the stomach, and even the liver sometimes, to come up into the chest.

Susan Spinner, MSN, RN: This causes lack of space above the diaphragm and the lungs and the heart actually get pushed to the side. So there’s no room for the lungs to grow.

Holly Hedrick, MD: FETO stands for Fetoscopic Endoluminal Tracheal Occlusion, F-E-T-O. This is a study that we’re currently performing at The Children’s Hospital of Philadelphia. It’s a feasibility study, which means that we want to see if we can perform it successfully and safely in mothers who are carrying fetuses with congenital diaphragmatic hernia.

The idea behind it is that a balloon is inserted into the airway to occlude the airway.

Susan Spinner, MSN, RN: That prevents lung fluid from escaping the lungs.

Holly Hedrick, MD: Which will cause a buildup of pressure.

N. Scott Adzick, MD, MMM: And that pressure that’s established is like a stinting force that distends the lung.

Susan Spinner, MSN, RN: That increases the number of air sacks, or alveoli, and also increases the surface area or makes the alveoli bigger.

Holly Hedrick, MD: Once they’re large, we actually remove that balloon so that they can go through the normal course of maturation. The FETO study will start off with an evaluation that is standard of care for any baby with a congenital diaphragmatic hernia.

Susan Spinner, MSN, RN: There would be a detailed telephone call in which we would gain their history information and the baby’s anatomical defect information. We would bring them into our center and they would have a comprehensive, one-day evaluation.

Lori J. Howell RN: The high resolution ultrasound. They would have the ultra-fast fetal MRI. Then they would have a fetal echocardiogram. And then they would meet with the high-risk obstetricians as well as the pediatric surgeons, neonatologist, social worker, genetic counselor, and essentially all the key members of our team.

Susan Spinner, MSN, RN: During the initial evaluation, it will be determined whether the mother and the fetus are eligible for the study, depending on certain anatomic criteria in the fetus and certain maternal factors in mom’s health history. That along with the associated potential risks for mom and for the baby will be detailed and discussed at the counseling session.

Holly Hedrick, MD: If all criteria are met, then there’s a chance that the mom would be offered this procedure.

N. Scott Adzick, MD, MMM: Those who are candidates and choose to go forward with this, it is a commitment. It’s an operation under a local anesthesia, or sedation at 20-30 weeks’ gestation.

Holly Hedrick, MD: It’s preformed in much the same way as other fetoscopic procedures. A small incision is made in the uterus, under ultrasound guidance. And then a trocar is placed so that it can line up with the fetal mouth.

A fetal bronchoscope is passed through this trocar and then into the baby’s airway. And then under direct vision, we actually blow up the balloon, and then detach it and leave it in place.

Julie Moldenhauer, MD: Moms stay in the Philadelphia area for a good three to four weeks afterwards so that we can prepare her for the balloon retrieval.

Holly Hedrick, MD: We need to follow really closely to watch how the lungs grow. To watch for any potential complications to make sure that the balloon remains in place. And then towards the end of gestation, around 34 weeks, we would like to remove the balloon.

Now there’s a couple of ways to do this. The first and the easiest way would be if we could puncture with a needle and then because the pressure behind it is stronger, have it just come out of the fetal mouth. And that would be attempted.

If that’s not successful, if we can’t just puncture it, the next step would actually to be to repeat the procedure that was performed before. Again another small incision after lining it up where the fetal mouth will be. And then passing a fetal bronchoscope into the airway. And this time it’s loaded with a grasper in order to pull that balloon out.

Susan Spinner, MSN, RN: Families would be required to deliver at the Special Delivery Unit at CHOP so that there would be the multi-disciplinary resources there to take care of mom and the baby when the baby is born.

Holly Hedrick, MD: The baby’s immediately intubated. The baby is immediately on a ventilator, and then we go through the course of things as usual. We’re trying to wean the ventilator. We’re trying to wean support and get the baby ready for surgery. All the babies will still need to have their diaphragmatic hernias repaired at some point when they’re stable.

Julie Moldenhauer, MD: Parents should anticipate that they will have a stay in the NICU that should be, you know, in the order of weeks if not months. We hope the tracheal occlusion will help to minimize some of these concerns that these neonates have right off the bat, but we are fully prepared that they are going to follow a course very similar to what a typical newborn with congenital diaphragmatic hernia faces.

N. Scott Adzick, MD, MMM: In addition, we would anticipate a commitment long term, or for of course those babies who survived, to be followed by us with the standard of care protocol we have that goes all the way through the Pulmonary Hypoplasia Program, which is that multi-disciplinary group that’s focused on children with diaphragmatic hernia problem and all the issues that they may have.

Holly Hedrick, MD: To see how they perform both neuro-developmentally and from a cardiopulmonary standpoint. And these visits will be scheduled at 6 months, 12 months and 2 years.

Julie Moldenhauer, MD: So our goal when families come to us for evaluation and consultation is that we provide them with enough information to decide what they think is the best course for their family and for their baby. And whether this is participation in the FETO Trial, or a typical postnatal repair, we hope that we provide enough information for the family that they are making the best decision for them.