June 03, 2011
Prenatal Surgery for Spina Bifida
Kangmin Daniel Lee, MD
For the first time, a significant clinical trial recently published in the New England Journal of Medicine, shows that fetal surgery can help babies with myelomeningocele.
Myelomeningocele is the most serious form of spina bifida, the most common congenital disorder of the central nervous system. A baby born with myelomeningocele has a spinal column not completely closed, which allows for the protrusion of the spinal cord.
Surgery to correct this disorder is typically performed after birth, but often cannot prevent progression of neurologic deficits or some of the other associated problems such as hydrocephalus or Chiari malformation. Prenatal surgery for myelomeningocele repair was first introduced in 1997.
In the study out of the University of California, San Francisco, 183 pregnant women were randomized to have prenatal or postnatal surgery performed. Results of the study show that prenatal surgery reduced the need for shunt placement 40 percent vs. 82 percent and resulted in improved mental development and motor function. However, prenatal surgery increased the risk for maternal complications and premature births. Despite this, children who received prenatal surgery were more likely to walk independently at 30 months, even though the lesion levels were on average, more severe.
The results from this study are clearly important and emphasize the possible advantages of prenatal surgery over postnatal surgery. However, not all the children in the study benefited from prenatal surgery and some had poor outcomes. Patient selection had to be done very carefully. Would improved outcomes be apparent if prenatal surgery was more widespread? Are the increased risks of premature birth and morbidity to the mother worth the trade off? Prenatal surgery would be highly specialized and would require a highly trained and dedicated team, while postnatal surgery is simpler and does not cause trauma to the mother.
The results of this study indicate that prenatal surgery for myelomeningocele shows potential. However, further research of this technique is clearly needed.