Prediction of NICU mortality in fetuses and neonates with Vein of Galen Malformation.

Background And Purpose: Vein of Galen malformation (VOGM) is a rare fetal arteriovenous shunt with presentations ranging from asymptomatic infancy to high-output cardiac failure and death. Prenatal percutaneous embolization is being explored in fetuses predicted to be at high risk for death in the Neonatal Intensive Care Unit (NICU). The purpose of this study is to (1) evaluate the reliability of previously reported measurements and (2) identify any novel imaging markers predictive of NICU mortality in a cohort of VOGM patients managed at our institution.

Materials And Methods: This was a single-center retrospective cohort study of fetuses and neonates with isolated VOGM evaluated at our hospital from 2016-2024. Patients with fetal and/or neonatal MRI had assessment of the narrowest mediolateral diameter of the straight or falcine sinus (SS-MD), ventriculomegaly, pseudofeeders, cerebral ischemia, and hydrops. Indexed combined cardiac output and tricuspid regurgitation severity were evaluated echocardiographically. Advanced post-processing MRI techniques were used to calculate the VOGM varix volume, brain parenchymal volume, and varix-to-brain volume ratio (VBR). Receiver Operating Characteristic (ROC) curves were used to determine cutoff values for predicting NICU mortality. All variables predicting NICU mortality were adjusted for age at MRI and delivery using regression analysis.

Results: Fourteen cases with pre-embolization MRIs were identified (6 fetal and 8 neonatal). NICU mortality was 29% (4/14). Survivors and non-survivors had significantly different SS-MD (6.6 vs 11.0 mm, p=0.007) and VOGM varix volume (4,145 vs. 12,758 mm3, p=0.014) respectively, however after adjusting for age at MRI and delivery, these differences were no longer statistically significant. However, VBR significantly differed between survivors and non-survivors (1.4% vs 7.7%, p=0.008, respectively) even after adjusting for age at MRI and delivery (p=0.038). A VBR >4.18% was 100% sensitive and 90% specific in predicting NICU mortality (AUC=0.95, p= 0.011) with a positive likelihood ratio of 10.

Conclusions: Previously reported imaging findings did not predict NICU mortality from VOGM in this cohort after adjusting for age at MRI and delivery. However, a VBR >4.18% strongly predicted NICU mortality in our cohort, suggesting that this novel parameter may help to identify VOGM patients who could benefit from fetal intervention.

Abbreviations: VOGM = Vein of Galen Malformation, NICU = neonatal intensive care unit, AUC = area under the curve, VBR = ratio of VOGM varix volume to brain parenchyma volume, SS-MD = mediolateral width of the straight or falcine sinus at its narrowest dimension, GA = gestational age, dGA = gestational age at delivery, mGA = gestational age at MRI, mPMA = post-menstrual age at MRI, CCI = combined cardiac index, MCA = middle cerebral artery, TR = tricuspid regurgitation, TOTAL = Tracheal Occlusion to Accelerate Lung Growth, CDH = congenital diaphragmatic hernia, ROC = receiver operating characteristic.