Longitudinal evolution of central nervous system anomalies in fetuses with open spina bifida fetoscopic repair and correlation with neurologic outcome

Abstract

Background: Open spina bifida is associated with central nervous system anomalies such as abnormal corpus callosum and heterotopias. However, the impact of prenatal surgery over these structures remains unclear. Objective: This study aimed to describe longitudinal changes of central nervous system anomalies before and after prenatal open spina bifida repair and to evaluate their relationship with postnatal neurologic outcomes. Study design: Retrospective cohort study of fetuses with open spina bifida who underwent percutaneous fetoscopic repair from January 2009 to August 2020. All women had presurgical and postsurgical fetal magnetic resonance imaging, at an average of 1 week before and 4 weeks after surgery, respectively. We evaluated defect characteristics in the presurgical magnetic resonance images; and fetal head biometry, clivus supraocciput angle, and the presence of structural central nervous system anomalies, such as abnormalities in corpus callosum, heterotopias, ventriculomegaly, and hindbrain herniation, in both presurgical and postsurgical magnetic resonance images. Neurologic assessment was performed using the Pediatric Evaluation of Disability Inventory scale in children who were 12 months or older, covering 3 different sections, namely self-care, mobility, and social and cognitive function. Results: A total of 46 fetuses were evaluated. Presurgery and postsurgery magnetic resonance imaging were performed at a median gestational age of 25.3 and 30.6 weeks, with a median interval of 0.8 weeks before surgery, and 4.0 weeks after surgery. There was a 70% reduction in hindbrain herniation (100% vs 32.6%; P<.001), and a normalization of the clivus supraocciput angle after surgery (55.3 [48.8-61.0] vs 79.9 [75.2-85.4]; P<.001). No significant increase in abnormal corpus callosum (50.0% vs 58.7%; P=.157) or heterotopia (10.8% vs 13.0%; P=.706) was observed. Ventricular dilation was higher after surgery (15.6 [12.7-18.1] vs 18.8 [13.7-22.9] mm; P<.001), with a higher proportion of severe ventricular dilation after surgery (≥15mm) (52.2% vs 67.4%; P=.020). Thirty-four children underwent neurologic assessment, with 50% presenting a global optimal Pediatric Evaluation of Disability Inventory result and 100% presenting a normal social and cognitive function. Children with optimal global Pediatric Evaluation of Disability Inventory presented a lower rate of presurgical anomalies in corpus callosum and severe ventriculomegaly. When analyzed as independent variables to global Pediatric Evaluation of Disability Inventory scale, the presence of abnormal corpus callosum and severe ventriculomegaly showed an odds ratio of 27.7 (P=.025; 95% confidence interval, 1.53-500.71) for a suboptimal result. Conclusion: Prenatal open spina bifida repair did not change the proportion of abnormal corpus callosum nor heterotopias after surgery. The combination of presurgical abnormal corpus callosum and severe ventricular dilation (≥15 mm) is associated with an increased risk of suboptimal neurodevelopment.