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

<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 (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. <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 rSO₂ 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 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,<i> p</i> = 0.04) and tended to have higher renal rSO₂ (80 vs. 65%,<i> p</i> = 0.09). The presence of diastolic backflow in the descending aorta was not associated with cerebral or renal rSO₂ 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.

<b><i>背景：</i></b> 对于左侧梗阻性病变（left-sided obstructive lesions, LSOL）患儿，升主动脉或降主动脉内出现逆向血流，可分别导致脑血流与肾血流减少。
<b><i>研究目的：</i></b> 本研究旨在比较左侧梗阻性病变患儿中，升主动脉血流为顺向与逆向者，以及降主动脉存在舒张期反流与无舒张期反流者的脑、肾组织血氧饱和度（tissue oxygen saturation, rSO₂）。
<b><i>研究方法：</i></b> 本研究基于2次超声心动图检查结果，根据升主动脉与降主动脉内的血流方向对研究队列进行分组。采用近红外光谱法（near-infrared spectroscopy）检测脑、肾组织血氧饱和度，并计算组织氧摄取分数（fractional tissue oxygen extraction, FTOE）。
<b><i>研究结果：</i></b> 本研究共纳入19例左侧梗阻性病变患儿，均于出生后0~28天入住新生儿重症监护病房（neonatal intensive care unit, NICU）。顺向血流组（n=12）与升主动脉逆向血流组（n=7）患儿在两次超声心动图检查中的脑rSO₂及FTOE水平均无显著差异。仅在首次超声心动图检查时，升主动脉逆向血流组患儿的肾FTOE更低（0.14 vs. 0.32，p=0.04），且肾rSO₂水平呈升高趋势（80% vs. 65%，p=0.09）。降主动脉存在舒张期反流与否，与首次（n=8）及第二次（n=10）超声心动图检查中的脑、肾rSO₂及FTOE均无关联。
<b><i>研究结论：</i></b> 左侧梗阻性病变患儿的升主动脉逆向血流与脑氧合状态无显著关联，而降主动脉舒张期反流亦与肾氧合状态无关。