Alterations in skull base anatomy in intrauterine and postnatal repaired myelomeningoceles

Purpose The aim of this study was to analyze the skull base anatomy of patients who underwent intrauterine or postnatal myelomeningocele repair and to determine its relationship with hydrocephalus. Methods This was a retrospective cross-sectional study that analyzed three groups: the postnatal group, 57 patients who underwent myelomeningocele repair up to 48 h after birth; the fetal group, 70 patients who underwent myelomeningocele repair between 19 and 27 weeks of gestation; and a control group (65). We compared the rate of hydrocephalus treatment, the clivus-supraocciput angle (CSA), and the Welcher angle. Results The mean CSA in the fetal group was 87.6 degrees, and the postnatal group was significantly different at 78.3 degrees (p < 0.0001). The control group (89.1 degrees) was significantly different from the postnatal group but not from the fetal group. The mean Welcher angle was not significantly different between the groups. There was an 8.5% rate of surgical treatment for hydrocephalus in the fetal group, compared with 73.6% in the postnatal group. Conclusions The CSA in the fetal group was larger than that in the postnatal group, which may explain the decrease in the prevalence of hydrocephalus in the fetal group.