263 Radiographic Structural Changes in Brain Anatomy of Pediatric Fetal Versus Postnatal Myelomeningocele Repair Patients

Abstract

INTRODUCTION: Postnatally repaired myelomeningocele (MMC) patients have twice the risk of needing shunt treatment for hydrocephalus compared to fetally repaired patients, however it is unknown why exactly this occurs as well as what structural brain changes may be predictive of hydrocephalus. We radiographically characterized anatomic changes in fetally vs postnatally treated infants to understand early developmental anatomy. METHODS: MRIs were characterized by two board-certified neuroradiologists for the following variables: 1) The ratio of ventricular-to-subarachnoid space (VSAR) using bifrontal (BF), left frontal lobe thickness (LV), and extra-axial (EA) spaces as parameters. 2) The ratio of 2 planes within the lateral ventricle (LVR). These ratios, elongation of the choroid plexus glomus and body, and Chiari were measured. RESULTS: 54 MMC repair patients met criteria, yielding 109 MRIs. In the one-to-three month time frame, VSAR at BF and LV parameters in addition to LVR were all significantly different in the fetally repaired group (n = 14) compared to the postnatally repaired group (n = 13, p<0.05). VSAR was not significantly different in early life. Chiari was significantly different in the early life and one-to-three month time between fetal and postnatal repair cohorts (p < 0.05). CONCLUSIONS: Fetally and postnatally repaired MMC brain MRIs were examined by two neuroradiologists to characterize differences in early brain development. This study identified significant differences in the ventricular to subarachnoid space ratio during the one-to-three month time point between fetally and postnatally repaired patients. We suspect that subarachnoid anatomy may be predictive of the need for surgical treatment of hydrocephalus.