Fetal Surgery Could Boost Outcomes in Severe Spina
WEDNESDAY, Feb. 9 (HealthDay News) -- Surgery to address the
most serious form of the spinal cord birth defect known as spina
bifida may be most effective if performed on the fetus, new -- and
potentially groundbreaking -- research suggests.
When successful, the surgery could mean the difference between a
life spent on crutches or not, experts say, since twice as many
spina bifida-affected children ended up walking on their own after
the fetal surgery versus those who were operated on after
But the delicate prenatal procedure also comes with hazards,
including much higher odds for premature delivery and its attendant
problems for newborns.
"While this is a very promising and quite exciting result for this disease, which is otherwise a very neglected disease, not all the patients were helped here, and there are significant risks," study senior author Dr. Diana Farmer, division chief of pediatric surgery at the University of California San Francisco, as well as surgeon-in-chief at UCSF Benioff Children's Hospital, said at a news conference held Wednesday. "So this procedure is not for everyone," she cautioned.
Nevertheless, Farmer added that "it would be responsible to
inform families that this [prenatal approach] would represent an
additional option in care that they can consider."
Surgery for this "myelomeningocele" form of spina bifida is
designed to close up an abnormal opening at the back of the baby's
spine. The opening results in spinal cord protrusion, which can
alter the movement of spinal fluid and wrench the brain stem down
into the skull's base, a development known as "hindbrain
Surgery to correct the condition has traditionally been
performed after birth.
However, the new report, published online Feb. 9 in the
New England Journal of Medicine, suggests that delicate surgery performed in utero actually reduces the subsequent post-delivery need for "shunting," or diverting, of fluid away from the child's brain.
The myelomeningocele form of spina bifida occurs in 3.4 of every
10,000 births, according to background information in the study.
The literal translation of spina bifida is "split spine," Dr. Alan
E. Guttmacher, director of the Eunice Kennedy Shriver National
Institute of Child Health and Human Development (NICHD) at the U.S.
National Institutes of Health, said at the press conference. He
noted that this "neural tube" defect -- which occurs early in
embryonic development -- typically gives rise to significantly
impaired infant motor function. Bladder and bowel control are also
compromised, and in its most severe form the defect prompts serious
weakness and/or full paralysis below the spinal cord opening.
Hindered spinal fluid circulation can ultimately be
life-threatening, the researchers noted, and 10 percent of infants
with the myelomeningocele form of spina bifida die.
To explore a potentially better way to treat the defect, the
team worked with 183 expectant mothers, all of whom were carrying
children affected by the defect and hindbrain herniation.
The women were divided into two groups: one set to undergo a
one- to two-hour prenatal surgery between 19 and almost 26 weeks of
gestation, and one to undergo a similar post-delivery surgery.
All of the offspring were then examined at 1 year of age, and
then again at 2.5 years of age.
Farmer noted that by year one, two infant deaths had occurred in
each of the two groups.
Nevertheless, the research team observed that the combined risk
for either death or a need for a shunt to divert brain fluid by 1
year of age was much lower among infants who had undergone the
in-utero surgery (almost 68 percent), compared with those in the
post-delivery group (about 98 percent).
Children in the prenatal surgery group also fared 21 percent
better on scores assessing mental development and motor function by
the 2.5-year mark, compared with the post-delivery surgery
And while only around 21 percent of children in the
post-delivery surgery group were ultimately able to walk without
orthotics or crutches, that figure rose to nearly 42 percent among
those in the prenatal surgery group.
Speaking at the press briefing, Dr. Catherine Y. Spong, chief of
the NICHD's pregnancy and perinatology branch, described one other
"remarkable finding": By 1 year of age, more than one-third of the
children in the prenatal surgery group showed no signs of hindbrain
herniation, compared to just a little more than 4 percent of those
in the group who underwent surgery after delivery.
But there were hazards, as well -- children who underwent the
prenatal procedure were more likely to be born preterm, at an
average of 34.1 weeks, compared with 37.3 weeks among the
"Prematurity is a significant risk," noted Farmer, who added that such a development can prompt the onset of dangerous respiratory distress syndrome. In fact, nearly 21 percent of the prenatal group had signs of this breathing disorder, compared with only about 6 percent in the post-birth surgery group.
In addition, mothers in the prenatal group faced a higher risk
for uteral thinning, with one-third experiencing thinning at
"Even though the children who underwent the surgery in uterus did much better overall, these risks both to the fetus and the mother cannot be ignored," said Farmer.
The research team also cautioned that not all women are ideal
candidates for the surgery. Specifically, those determined to be
severely obese (with a body mass index over 35) were not included
in the study -- a criteria that the authors suggested could exclude
about 10 to 13 percent of women. Down the road, this obstacle could
prove problematic, since maternal obesity is a known risk factor
for spina bifida in offspring.
The study also involved researchers from the Vanderbilt
University Medical Center in Nashville and the George Washington
University Biostatistics Center in Washington, D.C.
For more on spina bifida, visit the
U.S. National Library of Medicine.
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