Spinal level of fetal myelomeningocele: does it influence ventricular size?

Objective: Our objective was to determine whether the level of the spinal defect influences ventricular size in fetuses with myelomeningoceles.

Materials And Methods: Sonograms of 51 fetuses with open spina bifida were reviewed to determine the gestational age, ventricular atrial diameter, severity of posterior fossa deformity, and the level of the spinal defect. Four categories for spinal defect level were used: sacral, low lumbar, high lumbar, and thoracic. Regression models for ventricular atrial diameter were fit, adjusting for gestational age, posterior fossa deformity, and spinal defect level. A Fisher's exact test was used to investigate a relationship between the level of the spinal defect and the severity of the posterior fossa deformity.

Results: Spinal defect level was distributed among the four categories as follows: sacral (n = 7), low lumbar (n = 30), high lumbar (n = 10), and thoracic (n = 4). The level of the spinal defect did not significantly affect ventricular size (p > .1), and the level of the spinal defect did not show any relationship to the severity of the posterior fossa deformity (p > .8).

Conclusion: The level of the spinal defect does not independently affect the degree of ventriculomegaly or severity of the posterior fossa deformity in fetuses with myelomeningoceles.