“Pseudo-feeders” on fetal MRI predict outcome in vein of Galen malformations

Objective: While vein of Galen aneurysmal malformations (VGAM) can be diagnosed in the fetus, the challenge is predicting the occurrence of its two major complications: cardiopulmonary failure and encephalomalacia. This study attempts to determine which fetal brain MRI features might be used to predict the development of these complications at birth. Methods: The cohort was extracted from a prospectively-assembled database of VGAM cases managed at a single referral centre from 2000 to 2014. Of 251 patients with VGAM, 83 cases were diagnosed prenatally. A total of 58 patient charts having at least one fetal MRI were reviewed. Patterns of brain parenchyma, hydrocephalus and so-called middle cerebral artery (MCA) “pseudo-feeders” were correlated with cardiac failure, pulmonary hypertension and encephalomalacia at birth. Results: The median gestational age at fetal MRI was 32.3 WP (±2.3). Nine fetuses (16%) had encephalomalacia. Thirty-one fetuses (53%) had MCA pseudo-feeders. Twenty-six fetuses (45%) had prenatal hydrocephalus. Prenatal MCA pseudo-feeders were a risk factor for encephalomalacia at birth (p=0.001). MCA pseudo-feeders and hydrocephalus were risk factors for both severe cardiac failure (p=0.01 and p=0.04, respectively) and severe pulmonary hypertension (p=0.014 and p=0.05, respectively) at birth. Interpretation: MCA pseudo-feeders are the result of impaired cerebral blood flow, and are thus a risk factor for further brain-melting at birth. Their presence can be used for informing parents and as an aid in management decisions. This article is protected by copyright. All rights reserved.