The artificial placenta: Continued lung development during extracorporeal support in a preterm lamb model

Abstract Purpose An artificial placenta (AP) utilizing extracorporeal life support (ECLS) could avoid the harm of mechanical ventilation (MV) while allowing the lungs to develop. Methods AP lambs (n = 5) were delivered at 118 days gestational age (GA; term = 145 days) and placed on venovenous ECLS (VV-ECLS) with jugular drainage and umbilical vein reinfusion. Lungs remained fluid-filled. After 10 days, lambs were ventilated. MV control lambs were delivered at 118 (“early MV”; n = 5) or 128 days (“late MV”; n = 5), and ventilated. Compliance and oxygenation index (OI) were calculated. After sacrifice, lungs were procured and HE alveolar development was quantified by the area fraction of alveolar septal tips staining double-positive for both markers. Results Compliance of AP lambs was 2.79 ± 0.81 C dyn compared to 0.83 ± 0.19 and 3.04 ± 0.99 for early and late MV, respectively. OI in AP lambs was lower than early MV lambs (6.20 ± 2.10 vs. 36.8 ± 16.8) and lung injury lower as well (1.8 ± 1.6 vs. 6.0 ± 1.2). Double-positive area fractions were higher in AP lambs (0.012 ± 0.003) than early (0.003 ± 0.0005) and late (0.004 ± 0.002) MV controls. Conclusions Lung development continues and lungs are protected from injury during AP support relative to mechanical ventilation. Level of evidence n/a (basic/translational science).