Supplementary Material for: Cerebral Hemodynamics and Regional Oxygen Metabolism during Ductus Arteriosus Ligation in Preterm Infants

Introduction: Neurodevelopmental impairment is a growing concern for preterm infants who received surgical ligation of patent ductus arteriosus (PDA). We aimed to explore the cerebral hemodynamics during the critical period of PDA ligation. Methods: Very-low-birth-weight (VLBW) preterm infants who underwent PDA ligation were prospectively enrolled. Patients were monitored preoperatively and until 72 h post-ligation. Middle cerebral artery (MCA) flow, regional cerebral oxygen saturation (rcSO2), and cardiac output were measured through Doppler ultrasound, near-infrared spectroscopy, and electrical cardiometry, respectively. Using rcSO2 2 90th percentile of pulsatility or resistance index. Poor outcomes were defined as in-hospital death or neurologic disorders, either neuroimaging or functional abnormalities, upon discharge. Results: Thirty-two VLBW infants were examined, and 15 (46.9%) had poor outcomes. Infants with poor outcomes had significantly longer duration of cerebral hypoxia (5.4 [2.2–32.3] vs. 1.8 [0.4–5.6] %, p = 0.033) and worse hypoxic burden (2,118 [684–13,549] vs. 622 [88–1,669] %minutes, p = 0.027). In a linear mixed model, rcSO2 was positively correlated with arterial saturation (β 0.860, 95% CI: 0.649–1.070) and negatively correlated with abnormal MCA flow (β −5.287, 95% CI: −8.238 to −2.335). Conclusion: Longer duration of cerebral hypoxia and worse hypoxic burden post-ligation was associated with an increased risk of in-hospital mortality or neurologic disorders upon discharge in VLBW preterm infants.