Spina bifida: Promise and limits of fetal surgery

Noah Kipfmiller , 14, who has spina bifida, had surgery at Children's Hospital before he was born. Six other medical centers offer the procedure. CRAIG STERKEN
Noah Kipfmiller , 14, who has spina bifida, had surgery at Children's Hospital before he was born. Six other medical centers offer the procedure. CRAIG STERKEN
Posted: March 12, 2013

At 14, Noah Kipfmiller has begun to think about what he'd like to be when he grows up.

"Kind of like a video game designer," said the Bay City, Mich., eighth grader.

He does not ponder his distinction as the world's first person to have had successful fetal surgery for a devastating spinal cord birth defect.

"I have a scrapbook," his mother, Mellissa, said of the hoopla surrounding her son's 1998 birth. "I showed it to Noah. He's just not that into it yet."

Although Noah may not appreciate it, he is a measure of the success - and the implacable limits - of fetal surgery for severe spina bifida, which only recently ceased to be deemed experimental.

Noah was no bigger than a large apple when surgeons at Children's Hospital of Philadelphia opened his mother's womb, repositioned him, and pulled his skin over a hole in his back and spine.

Normally, surgeons close the hole after birth. Those babies typically have a brain malformation that causes fluid to build up in the skull - and paralysis below the waist.

Noah, in contrast, had no sign of the malformation. And he had good leg movement, or so it seemed at birth.

Still, it took an additional 13 years, ending with a landmark government study conducted at Children's, Vanderbilt University, and the University of California, San Francisco, to show that fetal surgery conveys clear benefits.

In the two years since that study finished, six other medical centers have begun offering the operation, while Children's, by far the leader, has done about 75 more cases, said Julie Moldenhauer, a high-risk-pregnancy specialist.

"Patients come from everywhere," she said, noting that a third who are evaluated actually qualify and opt for the surgery.

"Maternal–fetal surgery is a major procedure for the woman and her fetus," the American College of Obstetricians and Gynecologists wrote in January. "It should only be offered at facilities with the expertise, multidisciplinary teams, and services to provide the intensive care required for these patients."

Scott Adzick, now chief of surgery at Children's, trained with fetal surgery pioneers at UCSF.

Severe spina bifida, called myelomeningocele, was the first nonlethal condition they sought to treat in the womb.

In the United States, about 1,500 babies a year are born with the defect, which arises during embryonic development. Part of the bony spine fails to close, allowing the spinal cord to protrude through the middle to lower back.

The hole also allows cerebrospinal fluid to leak out, disrupting fluid pressure in the skull. The lower brain then sinks into the top of the spinal canal, becoming compressed. That can later cause problems with swallowing, speaking, and breathing. The brain also acts like a dam, causing fluid buildup, or hydrocephalus, in the skull.

In addition to prompt surgery to close the hole, newborns need a lifelong drain, or shunt, that is prone to infection.

Initially, Adzick said, UCSF researchers worried that covering the hole before birth would worsen the brain malformation and hydrocephalus.

But they theorized that intervening early - around 23 weeks into a 40-week pregnancy - was crucial to prevent cumulative nerve damage in the womb. Using lambs, they showed that repairing spina bifida-like defects early rather than late in gestation prevented hind limb paralysis at birth.

In humans, the fix proved more difficult.

Adzick's team sewed and sealed Noah's skin, as fragile as Kleenex, but it turned out not to provide enough padding for the spinal cord.

Although Noah's leg movement was vigorous at birth, it steadily deteriorated as his cord got stuck, or tethered, to adjacent tissue. At 7 months, when Adzick's team surgically freed the cord and implanted a cushion of muscle and fat, the damage was irreversible. Noah was largely paralyzed.

"We learned from Noah that we had to do a multilayer repair," Adzick said.

Noah's mobility was further compromised after hip surgery at age 4. After full-leg casts were removed, he accidentally fractured both knees.

With physical therapy, Noah learned to walk in leg braces and with wrist crutches, but it was grueling. When he was in fifth grade, Mellissa and her husband, Kevin, an automotive engineer, let Noah rely on a wheelchair full time. "He knew walking drew more attention to him than the wheelchair," Mellissa said.

The surgery has improved since Noah had it. But preventing disability is far from guaranteed.

In the $22.4 million government study of 183 babies, 42 percent of those who had fetal surgery could walk without assistive devices at 30 months, compared with 21 percent who had the postnatal surgery.

Surgery's biggest advantage turned out to be one the researchers did not initially predict: The brain rose back to its proper position in the skull. As a result, only 40 percent of fetal surgery babies needed a shunt at age 1, compared with 82 percent who had postnatal surgery.

Noah has never needed a shunt.

Noah was actually not the first to undergo the fetal repair.

In 1997, four spina bifida fetal surgeries were performed at Vanderbilt with "minimally invasive" techniques.

Instead of a four-inch opening in the womb, surgeons Joseph Bruner and Noel Tulipan made three small holes and inserted long flexible instruments to put a maternal skin graft over the fetal defect.

Minimally invasive technology has reduced the risks and recovery times of many types of surgery. But in the uterus - where leaks, bleeding, or infections can be disastrous - the approach was a mistake. Two fetuses died, and the survivors had no evidence of the skin patches. In Europe, the minimally invasive approach was equally unsuccessful.

That doesn't mean cutting the uterus open is low-risk. It often triggers premature labor and, despite anti-contraction drugs, premature birth. Children's Hospital had four deaths because of preterm delivery among its first 58 fetal spina bifida surgeries.

In the federal study, 62 percent of fetal surgery babies were preemies, compared with 12 percent who had postnatal surgery.

Researchers continue to seek less invasive early fixes. In rat experiments, Children's surgeon Alan W. Flake has injected bioengineered tissue to repair fetal spines.

"It's always been my view that, ultimately, it will be done using a minimally invasive approach," Tulipan said recently. "But we're not there yet."

Noah's favorite things include watching The Middle on TV, FaceTime with a friend who moved to Utah, and roughhousing with his little brother, Zachary.

His grades are OK, but don't ask his favorite subject. "I don't have one," he grumbled.

Through reunions at Children's Hospital, the Kipfmillers have bonded with several other fetal surgery families. Mellissa sometimes wishes another child had been the trailblazer - "If we weren't number one, I think Noah would be walking," she said - but she and her husband have no regrets.

"I would do it again in a heartbeat," she said. "He had the brain malformation in utero. That reversed after the surgery. It could have caused a long list of problems. Just to have that go away, it was a huge benefit."

Contact Marie McCullough at 215-854-2720 or mmccullough@phillynews.com.

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