Supplementary Material for: Aortic steal correlates with acute organ dysfunction and short-term outcomes in neonates with vein of Galen malformation

Introduction Vein of Galen aneurysmal malformation (VGAM) is a rare, congenital cerebrovascular malformation with high morbidity and mortality. Parameters to foresee clinical progression and allow individualized parent counseling are lacking. The aim of this study was to evaluate aortic steal measured by Doppler ultrasound as a prognostic parameter in these neonates. Methods Retrospective monocentric analysis of cardiac ultrasound exams before embolization in neonates with VGAM. Calculation of percentage of aortic steal by measurement of time-averaged maximum velocity above and below the zero flow-baseline by pulsed Doppler ultrasound at the preductal aortic isthmus. Evaluation of association of aortic steal with parameters of acute organ dysfunction (Bicêtre neonatal evaluation score (BNES), neonatal multiple organ dysfunction score (NeoMODS) and mortality and determination of correlation between aortic steal and cerebral damage on initial and follow-up cMRI. Results Twelve neonates were included, of which 3 died. Per 10 percentage point increase of aortic steal, BNES decreased by 1.64 (95 % confidence interval (CI) 1.28-2.0) points and the maximum observed NeoMODS increased by 1.25 (CI 0.94-1.57) points. The odds for mortality increased by 2.3 (CI 1.14-13.67) per 10 percentage point increase of aortic steal. There was a correlation between aortic steal and cerebral damage at baseline (white matter ρ (rho)=0.34, grey matter ρ=0.81) and follow-up (white matter ρ=0.80, gray matter ρ=0.72). Conclusion The degree of aortic steal in neonates with VGAM was highly associated with the severity of organ dysfunction, disease progression on cMRI, and mortality.