In-womb surgery offers crutch-free spina bifida hopes

Surgery that repairs spine abnormalities in fetuses several weeks before birth can double the chances that they can walk without crutches later on.
Written by Janet Fang, Contributor

Fetuses diagnosed with a common debilitating spine defect could receive surgery in the womb – doubling their chances of walking on their own as toddlers.

Spina bifida – “split spine” – is the most common birth defect of the central nervous system, affecting about 1,500 babies born each year in the US.

“This is game-changing for spina bifida,” says study author Diana Farmer of the University of California, San Francisco. “For a young couple, finding out their developing child has a problem is one of the most devastating things that can happen," she adds.

The most severe form, myelomeningocele (MY-ell-oh-men-NING-guh-seal, pictured), occurs when part of the spinal column doesn’t close around the spinal cord, failing to protect it during fetal development; amniotic fluid is known to damage the exposed spinal cord. ‘Cerebrospinal’ fluid could also leak though the open defect, causing herniation of the brainstem; this obstructs flow and results in fluid buildup injuring the brain.

About 10% of infants with myelomeningocele die. Those who survive the condition frequently suffer paralysis, cognitive impairments, bladder problems, and excessive fluid pressure in the brain.

Three fetal surgery centers participated in this trial called Management of Myelomeningocele Study (MOMS): Children’s Hospital of Philadelphia, Vanderbilt University, and the University of California San Francisco. It involved 158 babies.

Between 19 and 26 weeks in, a surgical team sealed the spina bifida lesion with multiple layers of the fetus’s own tissue. NPR explains:

Doctors must make a three-inch incision in the mother's uterus to expose the fetus, which is typically about four inches long at this stage. They then put the exposed piece of spinal cord – between the size of a raisin and an almond – back where it belongs, and suture layers of tissue to keep it in place and prevent cerebrospinal fluid from leaking out.

The results of the fetal surgery (prenatal), when compared with children who received the surgery days after they were born (postnatal):

  • Within a year after surgery, the children were less likely to need a shunt, a surgically implanted tube that drains fluid from the brain. 40% in the prenatal group received shunts, 83% in the postnatal group.
  • Two and a half years after the surgery, the children scored better on motor function tests. 42% in the prenatal group were able to walk without crutches, 21% in the postnatal group.

Researchers will follow up when the kids are 6-and-a-half and 10.

“This is the first time in history that we can offer real hope to parents who receive a prenatal diagnosis of spina bifida,” says study author N. Scott Adzick of the Children’s Hospital of Philadelphia. “This is not a cure, but this trial demonstrates scientifically that we can now offer fetal surgery as a standard of care for spina bifida.”

But there are risks: greater likelihood of being born several weeks earlier than the postnatal group, related breathing problems, and thinning or tearing at women’s surgical incisions, requiring Caesarean sections for later births [NYT].

Until doctors began correcting spina bifida in utero, fetal surgery had been reserved only for fatal defects out of concern for the safety of the mother [Time]. “I thought it was critically important to prove this really helped fetuses before we put the lives of mothers at risk,” says Farmer, who initiated the trial. “I know women will die from this procedure once it goes worldwide. It is a serious operation.”

The $22.5 million study appeared in New England Journal of Medicine yesterday.

Image: Center for Fetal Diagnosis and Treatment at the Children's Hospital of Philadelphia (for entire image, click here)

This post was originally published on Smartplanet.com

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