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

Background: 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. Objectives: Our aim was to compare cerebral and renal tissue oxygen saturation (rSO2)
between infants with LSOL with antegrade and retrograde blood flow in
the ascending aorta and with and without diastolic backflow in the
descending aorta. Methods: 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 rSO2 using near-infrared spectroscopy and calculated fractional tissue oxygen extraction (FTOE). Results:
Nineteen infants with LSOL, admitted to the NICU between 0 and 28 days
after birth, were included. Infants with antegrade blood flow (n = 12) and infants with retrograde blood flow in the ascending aorta (n = 7) had similar cerebral rSO2
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, p = 0.04) and tended to have higher renal rSO2 (80 vs. 65%, p = 0.09). The presence of diastolic backflow in the descending aorta was not associated with cerebral or renal rSO2 and FTOE during the first (n = 8) as well as the second echocardiogram (n = 10). Conclusions:
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.