New surgery: Tackling spina bifida in the womb

Robin Erb | Detroit Free Press

DETROIT — Kasey Hilton rested on the exam table with chilly ultrasound goo slathered on her belly, husband Mike sitting on the hard chair beside her. They waited for the word.

Boy or girl?

There were nursery colors and clothes to pick out. Names to consider.

Boy or girl?

The radiology tech said she wanted to consult with a doctor.

That seemed routine. This was the couple's first baby, Kasey Hilton recalled: "Looking back, ignorance was bliss."

There, on the screen was something the Whitmore Lake couple couldn't have imagined in their giddy wait for their baby's gender.

It was a pea-size protrusion on the spine of the fetus — a boy as it turns out. The words they heard instead: "spina bifida."

Meaning "split spine," the condition occurs when the spinal bones fail to fuse together as they should, almost like a zipper as a fetus grows. In the worst cases, the spinal cord and nerves protrude through the opening like a sac.

Now, the University of Michigan Health System has become one of 13 hospitals in the country to perform surgery to partially correct the malformation — not after the birth, but while the fetus is still inside the mother.

The first candidates were Kasey and Mike Hilton. She's a middle school language arts teacher; he's a chiropractor.

Following their first ultrasound, other tests confirmed that their baby had myelomeningocele, the most severe of the spina bifida diagnoses.

About 1,500 babies are born in the U.S. each year with spina bifida, according to the U.S. Centers for Disease Control and Prevention. While most children survive into adulthood with spina bifida, some must use walkers or crutches to walk. Others can't walk at all. Some are unable to use the restroom on their own, and some have learning disabilities as well.

The cause is uncertain.

For years, the diagnosis of spina bifida while a mom was pregnant meant a sort of waiting game. Doctors waited until the baby was a few days old, then operated on its spine to repair as much damage as possible.

The children often required additional surgeries to put into place shunts to drain the excess fluid that commonly builds up around the brain because of the deformation.

When all went well, there was no more damage to the spinal cord and the shunts drained fluid as they are supposed to.

But often, there were infections or malfunctions of the shunt, requiring more surgeries that, in turn, led to more complications, said Lisa Raman, director of the National Resource Center of the Spina Bifida Association of America.

"It becomes a very cyclical thing," she said.

Fetal surgery to mend congenital defects isn't new. But until recently it was unclear whether the in utero procedure to reduce the damage from spina bifida had any more benefit than surgery just after birth.

So in 2003, the Management of Myelomeningocele Study (MOMS) was funded by the National Institutes of Health. After several years and 183 babies, it was clear that closing the defect in utero reduced the need for shunts after birth and boosted the child's chances of walking independently.

As the study progresses, doctors hope to find out whether the procedure reduces the odds of learning disabilities as well.

An easy decision

At U-M, doctors had been watching the study closely. When the first results were released in 2011, they had already begun assembling a team to replicate the same rigorous protocols set out by the clinical trial.

Dr. Marcie Treadwell, director of the Fetal Diagnosis Center at U-M, talked with the Hiltons last year after tests confirmed what the ultrasound suggested. She specializes in high-risk pregnancies.

"She said, 'Your baby boy would get the exact same surgery after he's born, but (with this procedure) he would have the opportunity to heal inside the womb instead of outside it,'" Kasey Hilton recalled.

There is a downside, Treadwell warned them. The study also found that babies who undergo fetal surgery are more likely to be born earlier than expected and that brings with it the risks that accompany preterm births. Additionally, their mothers must give birth by C-section from then forward.

Kasey Hilton said the decision was easy.

On July 29, doctors wheeled her into an operating room at C.S. Mott Children's Hospital at U-M at 9:30 a.m.

Surgeons first opened her abdomen and uterus. With Hilton's vitals still steady, doctors then began the surgery on the 23 1/2-week fetus inside her.

Now separately anesthetized, the single-pound fetus was gently turned and held into place by gloved surgical hands. Its tiny spine was exposed to a pediatric neurosurgeon, who separated some of the abnormal tissue, then closed the skin over the exposed portion of the spine while making sure not to disturb the underlying nerve tissue in the spinal cord.

A specialist monitored the ultrasound for signs of fetal distress.

One anesthesiologist monitored mom; a second anesthesiologist — working with a pediatric cardiologist and maternal fetal medicine doctor — was responsible for the fetus.

It's a "delicate, intensive, highly involved procedure," said Dr. Julie Moldenhauer, who trained at Wayne State University. "It's a bit tense, yes."

As part of her work at the Center for Fetal Diagnosis and Treatment at the Children's Hospital of Philadelphia, one of the participating centers in the MOMS study, Moldenauer helped write the guidelines for the procedure.

In Ann Arbor last summer, with the baby tucked safely back inside his mother, Kasey Hilton's uterus and abdomen were stitched closed in multiple layers — more so than in most other surgeries — to ensure a water-tight closing that would withstand the movements of a growing fetus.

The entire procedure lasted several hours — but it had taken just 33 minutes to operate on the 1-pound fetus, Treadwell said.

Four days later, Kasey Hilton, who since has begun to blog about her experience, went home. Inside her, her little boy was healing.

"It's funny. I joke that he had the surgery — I was just in the way," Hilton said.

Not a cure

The surgery does not cure spina bifida.

"It's not going to take a child back to where they would be without a neural tube defect. What it does is improve the outcome for some kids," Treadwell said.

In fact, the Spina Bifida Association, while watching the results of the ongoing trial, neither endorses nor advises against the surgery, the association's Raman said.

The study will continue as the babies in the study are followed long-term to determine whether the procedure also reduces learning disabilities.

These days, Carter William Hilton is a cooing ball of wiggly energy. He had a shunt surgery Dec. 15, but doctors have told the Hiltons that the in utero surgery significantly boosted Carter's odds of walking on his own.

Last week, he was back in the hospital for a "bad bug" — nothing to do with his spina bifida, the Hiltons were told.

After everything else, Kasey Hilton said, chuckling, "This, we can deal with."