By Stephanie Stemmler
Spina bifida is a condition that affects the spine during the growth and development of a fetus. As the brain and spinal column begin to form, a portion of the spine doesn’t close completely. The resulting opening in the spine leaves the spinal cord and nerves exposed. In the most severe form of spina bifida, called myelomeningocele, a portion of the spinal cord and its nerves protrude from this opening.
Spina Bifida: making Repairs Before Birth
As the fetus grows in the uterus, these fragile nerves are exposed to surrounding amniotic fluid. And that exposure can cause damage, leading to paralysis or other mobility problems after birth, as well as bladder and bowel complications. The opening’s location can determine the kinds of complications that arise; for those located higher on the spine, hydrocephalus, a build-up of excess fluid in the brain, is a possibility.
Before the 1990s, treatment for severe spina bifida involved postnatal surgery—a procedure performed on a newborn after delivery. Though it closed the spinal cord to help prevent infection—and could treat hydrocephalus with a shunt to drain fluid—the procedure could not repair already damaged nerves. Consequently, children born with spina bifida faced a number of complications as they grew.
A leap forward in treatment
In 1997, the first prenatal surgery to repair spina bifida complications—done while the fetus was in the uterus—took place at Vanderbilt University Medical Center. Similar surgeries were subsequently performed at a few, select medical institutions in the U.S.
In 2011, results of a major study sponsored by the National Institutes of Health (NIH) found that prenatal repair of severe spina bifida resulted in better outcomes than surgery after birth. Specifically, the study found that prenatal surgery not only improved the chances that a child could walk independently, but it also showed that the need for a shunt to divert excess fluid from the brain was reduced by 50% when compared with those children who underwent surgery after birth. A follow-up study, published in 2020, noted the long-term physical and emotional advantages of prenatal surgery for the condition.
A delicate dance
“Severe spina bifida occurs in about one in 1,000 pregnancies,” says Anthony Odibo, MD, Washington University maternal-fetal medicine specialist at the Women & Infants Center at Barnes-Jewish Hospital, Washington University Physicians and St. Louis Children’s Hospital. “When we use prenatal surgery to treat the condition, we are working to care for the unborn baby while protecting the health of the mother.” Odibo also is interim co-director of the Fetal Care Center, part of the Women & Infants Center.
Traditionally, prenatal surgery for spina bifida is what’s known as an “open” procedure. At the Fetal Care Center, Washington University pediatric surgeon Jesse Vrecenak, MD, and Washington University pediatric neurosurgeon Jennifer Strahle, MD, work together to repair spina bifida complications. Vrecenak describes the procedure this way: “In an open surgery, we make a large incision across the mother’s abdomen, much like we do with a cesarean section. We then open the uterus, turn the baby so that the back is facing upward and lift the uterus partially out of the abdominal cavity. Dr. Strahle then places the protruding sac containing spinal cord and nerves into the spinal canal and closes the surrounding tissue and skin over the opening. Once that part of the procedure is completed, we then close the incisions in the mom’s uterus and abdomen.”
The procedure is much like a choreographed ballet performed inside an operating room, each specialist’s role carefully considered. The Fetal Care Center uses a dedicated operating room for fetal surgeries that is large enough to accommodate an anesthesia team for mom and fetus, a fetal cardiologist, pediatric surgeons, a pediatric neurosurgeon, maternal-fetal medicine specialists and multiple nursing professionals. “We use a team of this size to ensure that we provide the highest level of care for both patients during a complex procedure that requires surgical, neurosurgical and newborn-medicine expertise,” notes Strahle.
She adds: “If we can surgically close the opening in the spine and put the spinal cord and nerves in their proper place before a baby is born, we can prevent or minimize the progressive nerve damage that would occur if we waited until after delivery.”
Open surgery for spina bifida is usually performed between 24 and 26 weeks of pregnancy. After discharge from the hospital several days later, the pregnant patient must limit activity to bed rest, which helps deter the risks of premature birth and uterine rupture. She also must reside with a support person and remain within 30 minutes of the hospital. “The benefit of open fetal surgery is proven in high-caliber studies funded by the NIH,” says Odibo. After such a procedure, however, Odibo notes, “the patient will need to deliver the baby and all future babies by cesarean section.”
The Fetal Care Center offers moms and babies excellent outcomes after open surgical repair. Preterm delivery rates and incidences of fluid leakage are lower than those reported in the national clinical trial. “We’re proud of the expertise we can offer our patients,” says Odibo.
Surgeons at the Fetal Care Center now are able to perform a less invasive prenatal procedure for spina bifida. Called fetoscopic repair, it differs from open surgery in the number of incisions required and it offers additional benefits.
During fetoscopic surgery, a surgeon makes an incision in the abdomen similar to the one used in open surgery. But instead of using another large incision to open the uterus, two smaller incisions are made; they allow surgeons to insert specialized instruments inside the uterus. These tools provide ultrasound images to the team of surgeons, offering precision guidance.
“Fetoscopic surgery allows some patients to preserve their ability to deliver vaginally,” says Vrecenak. “It also gives them the option of returning home for the duration of their pregnancy after surgery.” Specialists at the Fetal Care Center work with families to determine the best surgical repair option. “We offer both open and fetoscopic,” Vrecenak says. Strahle notes: “Not every baby is a candidate for fetal surgery. We discuss all available options with our patients.”
After delivery, babies that have had prenatal surgery are cared for in the St. Louis Children’s Hospital newborn intensive care unit. Though there is no known cure for spina bifida, the team at the Fetal Care Center notes that various treatment options may prevent significant problems and can help manage the effects of the disease. “Fetal surgery offers a once-in-a-lifetime opportunity to prevent some complications rather than simply treat the disease,” notes Vrecenak. “If we can prevent nerve damage while a baby is still in the womb, outcomes are better when that child is born.”