Spina Bifida Prenatal Repair: Performing Surgery in the Womb
In the United States 18 babies out of 100,000 live births will have a myelomeningocele, often referred to as spina bifida, which is a congenital defect of the spine and spinal cord. Spina bifida occurs 25-29 days after conception when the baby’s spinal cord fails to develop or close properly and is exposed through a gap in the backbone, which can cause weakness or paralysis in the legs, incontinence, learning disabilities and hydrocephalus (water on the brain).
We spoke with Dr. Emanuel (Mike) Vlastos (pictured left), Medical Director of Fetal Therapy, and Dr. Paul Grabb (pictured right), Section Chief and Neurosurgeon, about the advancements in fetal surgery that make it possible to perform surgery in the womb before the baby is even born.
Dr. Vlastos has performed hundreds of fetal procedures and is internationally known for his expertise in fetal medicine, particularly prenatal treatment for spina bifida. Dr. Grabb is board certified by the American Board of Neurological Surgery and the American Board of Pediatric Neurological Surgery, and operated on neonates and children with spina bifida for over twenty years.
How is spina bifida treated in the womb?
Dr. Vlastos: We're very fortunate to live in the 21st century and offer cutting-edge options to our patients. Until early 1997, the only option was for a mother to give birth to her child and then have the spina bifida repaired at that time. Today, we can do that repair in utero.
Provided both mom and baby are candidates, we offer repair between 24-26 weeks of pregnancy where we open up the mother’s abdomen, open the uterus like a C-section and expose the baby's back so Dr. Grabb can close the spine.
Dr. Grabb: After the woman’s uterus is open and the fetus floats to the top of the uterus, Dr. Vlastos maneuvers the baby so the back is exposed to the neurosurgeon. Dr. Vlastos holds the baby as still as possible while the neurosurgeon make the repair.
The neurosurgical part of it is very brief. The vast majority of the procedure is spent carefully opening and closing the uterus, so that mom and baby stay safe.
From a technical standpoint, the neurosurgical part is very straightforward and the closure procedure is actually easier to perform in the womb than after the baby is born because the baby is closed up and put back in the uterus, and hence, underwater, I don’t have to worry as much about spinal fluid leakage, keeping a sterile bandage on the incision or infection. I think that’s why these incisions heal so beautifully, because they’re going back to a sterile underwater environment.
Dr. Vlastos: After surgery, the mother needs to stay in the hospital for 4-5 days, so we can monitor her for preterm labor. After being discharged from the hospital, she can return home (if she lives within a 50 mile radius) and finish her recovery for another two weeks. The mother will need to stay in the Kansas City area if she lives more than 50 miles away. It is imperative another adult is with her during this time because if a complication were to occur someone has to help get that mom to the center to be evaluated. After that two week period, the mother will visit her OB every week for an ultrasound to make sure there are no signs of preterm labor. Most moms will give birth between 33-34 weeks, but the goal is for the pregnancy to be promoted until 37 weeks and deliver the baby via C-section.
Not everyone is a candidate for prenatal repair. How does a mom and her baby qualify?
Dr. Vlastos: First, we need know the genetic structure of the baby before we can even consider performing the prenatal repair. An amino synthesis will determine if the baby in the womb has normal genes. If the baby has no other issues outside of spina bifida than the child would be considered for surgery before birth.
However, the mother also has to be a healthy person. To be a candidate for surgery, mom can’t have insulin dependent diabetes, have chronic hypertension, she can't have the AIDS virus or hepatitis viruses. She also can’t have had a pre-term birth in the past, because undergoing surgery puts her at pre-term risk. If she’s already had one baby early, she’s more than likely to have this baby early too.
What are the risks of prenatal repair?
Dr. Vlastos: Even though prenatal repair has been around for two decades, it didn’t start gaining national attention until 2011 when The New England Medical Journal posted about the Management of Myelomeningocele Study or MOMS trial, which compared prenatal and postnatal repair. The study concluded that prenatal surgery had long-term benefits, although the surgery did come with risks.
First, there is risk to the mother. Prior to considering this procedure, we stress to the mom that we’re changing her body forever and how she’s going to have children in the future. Women who've undergone prenatal repair must deliver her child and any future children via C-section, because the scar created on the uterus has the potential to open up if she should labor.
For the baby, the risk is prematurity or even death. In comparison, kids that undergo postnatal repair are usually born around 38 weeks. They’re near term and come out sucking, swallowing and breathing on their own. Babies that undergo prenatal repair are usually delivered at 33-34 weeks. So you’re trading some prematurity to have a prenatal repair.
What are the benefits of prenatal repair?
Dr. Vlastos: The MOMS Trial helped answer that question as well. While there is no cure for spina bifida, repairing the spine in the womb can minimize the spinal defect.
Prenatal surgery also lowers the risk for a shunt. For babies that have surgery after birth, 82 percent will require a shunt to be placed in the brain. This is due to the formation of water on the brain or hydrocephalus. The shunt drains the fluid from the baby’s brain to the peritoneal cavity in the abdomen.
Because a shunt is a piece of hardware it can clog, get infected or break with a national 40 percent rate of some complication in the first year of life.
For babies that undergo prenatal repair, only 40 percent would need a shunt placement in their first year of life. Now that’s not zero percent, but the risk of needing a shunt is cut in half.
Dr. Grabb: Having hydrocephalus and a shunt is a tremendous burden on the kids, the family and the health care system just on the cost of putting them in, maintaining them and taking care of the problems that almost inevitably develop. The MOMS Trial showed babies that underwent prenatal repair had more mobility, more movement in the legs and better neurologic outcomes.
Another benefit about closing the spina bifida prenatally is the child is healed and sealed at birth. The mother can bond, hold and nurse her child without worrying about a fresh incision or spinal defect she can’t put pressure on. Also, there is no fresh incision that could get infected.
Did you ever think you would perform surgery in the womb?
Dr. Vlastos: No, not at all. I was a family doctor in the middle of Wyoming. I had heard and read about it, but I never thought I'd be a part of it. It's been a life-changer for me and hopefully I can continue to spread the word and push the science.
Dr. Grabb: I was an extreme skeptic when it first came out. But the more I saw these kids and talked to the people doing it and now having done it and seen these babies, it's an option that should be seriously considered. It’s also important to note that I couldn’t perform this surgery without the entire team.
Dr. Vlastos: Truly the heart and soul of the Fetal Health Center happens to be the nurse coordinators and the sonographers. That's a fact.
With respect to fetal interventions, you have four different services coming together to help one woman and one baby. First, you need a neurosurgeon to fix the spine. Second, and just as important, you need an anesthesiologist to make sure mom is stable through surgery. Third, is the nursing staff who help with the surgery, who take care of patients before surgery, take care of patients postpartum and take care of the babies. Lastly, you have obstetrical services, which is my role. I help coordinate the care during the surgery, keep an eye on the baby, assist the neurosurgeon, and communicate with anesthesia and nursing care. It truly is a team effort at its best with respect to surgical intervention.
What makes the Elizabeth J. Ferrell Fetal Health Center at Children’s Mercy unique?
Dr. Vlastos: Our Fetal Health Center is reflective of other centers around the U.S., but what makes us unique is that we’re one of the first to have a fetal center located inside a children's hospital. That means mom can give birth right here in the hospital, so baby is always close by.
Sometimes there are maternal reasons why mom can’t deliver here at Children’s Mercy and she needs expertise in an adult hospital. When that happens she can give birth at Truman Medical Center across the street, which is connected to the Fetal Health Center by the Gary Dickinson Bridge of Hope walkway bridge. This allows both families and staff to walk back-and-forth keeping everyone close.
We couldn’t do any of this without the community who have supported this program and a staff of great people. It really is homegrown.
How does a mother decide if prenatal surgery is right for her and her baby?
Dr. Vlastos: Just because mom and baby are a candidate it doesn’t mean it’s the right thing to do. It’s not an obligation to have the surgery before birth, it’s an option and a choice.
Dr. Grabb: There's not a right or wrong answer. We're not here to convince anybody of having the surgery, we're here to provide the information about the risks and the benefits, answer any questions and let the families make the decision that’s best for them.
Dr. Vlastos has been part of more than 85 prenatal repairs, 15 of which were performed at Children’s Mercy from November 2017- April 2019. Of the 15 surgeries, one child is still in gestation while the other 14 babies are healthy and growing. Only one baby has required a shunt and two have undergone endoscopic third ventriculostomy.
Read Mary Kate's story: Fetal Surgery Gives Babies a New Start After Spina Bifida.