Children born with spina bifida often need a shunt inserted in their brain to help drain excess fluid as a result of the condition. For some children, this is their second surgery after one while in utero to correct the spinal condition itself -- a procedure that is dangerous for both mother and baby. File photo by UPI |
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BETHESDA, Md., Sept. 15 (UPI) -- Previous research has shown that surgery to correct spina bifida in a fetus while still in the womb can prevent complications from the condition, as well as prevent later surgery after birth. Researchers found in a new study, however, that fetuses with enlarged ventricles in their brain are less likely to benefit from the risky surgery because they'll likely need a surgical procedure after they are born regardless.
Performing surgery on fetuses with spina bifida, a condition where the spinal column does not close around the spinal cord, is risky. It often can prevent symptoms of the condition, which include learning difficulties, urinary and bowel problems, issues walking, and buildups of fluid on the brain.
Spina bifida can be detected and corrected during pregnancy, however surgery on fetuses in utero can be dangerous for both the baby and the mother.
"A major rationale for performing the surgery is to avoid having to place a shunt [to divert fluid from the brain] later on," said Dr. Rosemary Higgins, a researcher at the National Institute of Child Health and Human Development, in a press release. "If it's likely that a second surgery will be needed anyway, then it doesn't appear that the potential benefits of an initial fetal surgery outweigh the risks."
Researchers considered data on mothers pregnant with children with Myelomeningocele, the most serious form of spina bifida, which causes the spinal cord to protrude through an opening in the spine.
The researchers randomly assigned 183 mothers either to a prenatal surgical group or one planning postnatal repair. MRI scans of the fetuses' brains were taken to determine whether a shunt might be needed to divert fluid from the brain.
Regardless of the surgical group the mothers were placed in, 72.5 percent of the prenatal surgical group and 97.8 percent of the postnatal group met the criteria for what researchers determined as the primary outcome of their analysis -- defined as whether a child died, had a shunt placed during the first year after birth, or met the study's criteria for when to place a shunt. Overall, 44 percent of fetuses had shunts placed during prenatal surgery, as opposed to 83.7 percent of the postnatal group.
The researchers found, based on MRI data, that fetuses in both groups with more enlarged ventricles were likely to need surgery after birth for the placement of a shunt.
For the prenatal surgery group, shunts were eventually placed in 20 percent of those with ventricles less than 10 mm, 45.2 percent with ventricles from 10 mm to just below 15 mm, and 79 percent with ventricle size of 15 mm or greater. In the postnatal group, the three ventricle sizes resulted in 79.4 percent, 86 percent and 87.5 percent of fetuses receiving shunts.
Based on the potential for future need, researchers determined the best candidates for surgery among the fetuses -- that is, those least likely to need a second surgery after being born -- were those with smaller ventricles.
"These results indicate that physicians should proceed with caution before recommending in utero surgery for a fetus with enlarged ventricles," Higgins said.
The study is published in the Journal of Neurosurgery: Pediatrics.
