Supplementary Material for: Cerebral and Renal Oxygen Saturation Are Not Compromised in the Presence of Retrograde Blood Flow in either the Ascending or Descending Aorta in Term or Near-Term Infants with Left-Sided Obstructive Lesions

<p><b><i>Background:</i></b> In infants with left-sided obstructive lesions (LSOL), the presence of retrograde blood flow in either the ascending or descending aorta may lead to diminished cerebral and renal blood flow, respectively. <b><i>Objectives:</i></b> Our aim was to compare cerebral and renal tissue oxygen saturation (rSO<sub>2</sub>) between infants with LSOL with antegrade and retrograde blood flow in the ascending aorta and with and without diastolic backflow in the descending aorta. <b><i>Methods:</i></b> Based on 2 echocardiograms, the study group was categorized according to the direction of blood flow in the ascending and descending aorta. We measured cerebral and renal rSO<sub>2</sub> using near-infrared spectroscopy and calculated fractional tissue oxygen extraction (FTOE). <b><i>Results:</i></b> Nineteen infants with LSOL, admitted to the NICU between 0 and 28 days after birth, were included. Infants with antegrade blood flow (<i>n </i>= 12) and infants with retrograde blood flow in the ascending aorta (<i>n</i> = 7) had similar cerebral rSO<sub>2</sub> and FTOE during both echocardiograms. Only during the first echocardiogram, infants with retrograde blood flow in the ascending aorta had lower renal FTOE (0.14 vs. 0.32,<i> p</i> = 0.04) and tended to have higher renal rSO<sub>2</sub> (80 vs. 65%,<i> p</i> = 0.09). The presence of diastolic backflow in the descending aorta was not associated with cerebral or renal rSO<sub>2</sub> and FTOE during the first (<i>n</i> = 8) as well as the second echocardiogram (<i>n</i> = 10). <b><i>Conclusions:</i></b> Retrograde blood flow in the ascending aorta was not associated with cerebral oxygenation, while diastolic backflow in the descending aorta was not associated with renal oxygenation in infants with LSOL.</p>