Objective: To describe the development of an artificial placenta (AP) system in sheep with learning curve and main bottlenecks to allow survival up to one week. Methods: A total of 28 fetal sheep were transferred to an AP system at 110–115 days of gestation. The survival goal in the AP system was increased progressively in three consecutive study groups: 1–3 h (n = 8), 4–24 h (n = 10) and 48–168 h (n = 10). Duration of cannulation procedure, technical complications, pH, lactate, extracorporeal circulation (EC) circuit flows, fetal heart rate, and outcomes across experiments were compared. Results: There was a progressive reduction in cannulation complications (75%, 50% and 0%, p = 0.004), improvement in initial pH (7.20 ± 0.06, 7.31 ± 0.04 and 7.33 ± 0.02, p = 0.161), and increment in the rate of experiments reaching survival goal (25%, 70% and 80%, p = 0.045). In the first two groups, cannulation accidents, air bubbles in the extracorporeal circuit, and thrombotic complications were the most common cause of AP system failure. Conclusions: Achieving a reproducible experimental setting for an AP system is extremely challenging, time- and effort-consuming, and requires a highly multidisciplinary team. As a result of the learning curve, we achieved reproducible transition and survival up to 7 days. Extended survival requires improving instrumentation with custom-designed devices.
Background/Objectives: Pneumothorax can be a major complication of neonatal lung diseases. We aim to delineate trends and describe the main outcomes related to pneumothorax in very preterm infants (VPI). Methods: Preterm infants < 32 weeks of gestation admitted in two-level III neonatal intensive care units (1995–2019) were included. Risk factors and outcomes were assessed by logistic regression and adjusted for gestational age (GA). Results: In total, 4271 VPI with a mean GA of 28.7 ± 2.3 weeks were evaluated. Pneumothorax was diagnosed in 174 patients (4.1%, 95% Confidence Interval (CI) 3.5–4.7) with its incidence inversely proportional to GA: 9.9% in 23–25 w and 2.1% in 30–31 w (p < 0.001), but stable over the years 1995–1999 (5.2%) and 2015–2019 (4.2%) (p = 0.309). Patients with pneumothorax exhibited higher rates of severe intraventricular hemorrhage (IVH) (Odds Ratio (OR) = 2.0 (95%CI 1.3–3.1), p = 0.003), bronchopulmonary dysplasia (OR = 2.7 (95%CI 1.7–4.4), p < 0.001), and death (OR = 8.5 (95%CI 6.2–11.6), p < 0.001). Independent risk factors for pneumothorax were GA, prolonged premature rupture of membranes, and intubation in the delivery room. The composite outcome of death or severe IVH was higher in patients with pneumothorax with an adjusted OR = 6.7 (95%CI 4.7–9.6), p < 0.001. Although VPI mortality has significantly decreased over the years (20.3% 1995–1999 and 11.7% 2015–2019, p < 0.001), we found no significant difference in pneumothorax-related deaths. Conclusion: Pneumothorax remains a serious threat to VPI, leading to a higher incidence of morbidity, and mortality attributable to this complication has not decreased. Preventive strategies and early recognition are essential for improving disability-free survival in VPI.