Prevalence of supratentorial anomalies assessed by fetal magnetic resonance in fetuses with open spina bifida.

Abstract

OBJECTIVES\nTo determine the prevalence of brain anomalies in fetuses eligible for prenatal open spina bifida (OSB) repair at the time of preoperative assessment, and to explore the relationship with the features of spinal defect.\n\n\nMETHODS\nRetrospective cross-sectional multicentric study in fetal medicine centers on fetuses undergoing OSB fetal surgery repair. Magnetic Resonance (MR) images obtained as part of the pre-surgical assessment were re-evaluated including: 1) the type and area of the defect and its anatomical level, 2) the presence of any structural Central Nervous System (CNS) anomaly, and abnormal ventricular wall, and 3) fetal head and brain biometry. Binary regressions were performed and data was adjusted by type of defect, upper level of the lesion (ULL), gestational age (GA), and fetal medicine center. A multiple logistic regression was done to define parameters associated to the presence of these brain anomalies.\n\n\nRESULTS\nAmong 115 fetuses, 91 had myelomeningocele and 24 myeloschisis. Anatomical level distribution was 7 thoracic, 13 L1-L2, 58 L3-L5 and 27 sacral. Median GA at MR was 24.7 (23.0-25.7) weeks. Overall, 52.7% of cases had at least one additional brain anomaly. Abnormal corpus callosum (CC) was observed in 50.4% and anomalies in the ventricular wall in 19.1%, of which 4.4% had nodular heterotopia. Factors independently associated with at least one brain anomaly were sacral level (OR 0.51, p=0.043, CI 0.26-0.97); ventricular width (OR 1.23, p=0.005, CI 1.07-1.43); and abnormal cavum septum pellucidum (OR 3.76, p=0.031, CI 1.13-12.48).\n\n\nCONCLUSIONS\nHalf of fetuses with OSB assessed for fetal spina bifida repair had an abnormal CC and/or an abnormal ventricular wall prior to prenatal repair. The likelihood for abnormalities is higher with higher lesions, and wider ventricles. These findings highlight the importance of a detailed CNS evaluation of fetuses with OSB. This article is protected by copyright. All rights reserved.