M. A. Coughlin1, N. L. Werner1, K. Marchetti1, L. Pierce1, T. Major1, G. B. Mychaliska1 1University Of Michigan,ECLS Laboratory,Ann Arbor, MI, USA
Introduction: Recreating the intrauterine environment with an extracorporeal artificial placenta (AP) to treat extreme prematurity is a promising strategy. The aim of this study was to assess lung development during AP support.
Methods: Institutional guidelines for animal research were followed. AP lambs of estimated gestational ages 116-120 days (term=145 days) were cannulated for VV-ECLS (internal jugular vein drainage and umbilical vein reinfusion) on placental support and delivered. They were intubated and the endotracheal tube filled with fluid and clamped (n=3) or held at a constant pressure of 8cmH2O (n=2). Tissue control (TC) animals were delivered and immediately euthanized. These were divided into early gestational age (115-122 days, n=4) and later gestational age (123-129 days, n=3). A bronchoalveolar lavage was obtained during necropsy on all animals and spun down to remove the solid cell component. The remaining fluid was used to obtain ELISA assays for surfactant related proteins B and C (SPB/SPC).
Results: The AP animals survived an average of 7 days. Levels of SPB in early vs. late tissue controls were 37.3±2 vs. 44.6±1.4 pg/ml (p=0.002). Levels of SPC in early vs. late tissue controls were 12.7±2 vs. 17±5.6 pg/ml (p=0.07). The average concentration of SPB in the AP lambs vs. later tissue controls was 41.1±5.5 vs. 44.6±1.4 pg/ml (p=0.24). The average concentration of SPC in the AP lambs vs. later tissue controls (Figure) was 22.4±1.8 vs. 17±5.6 pg/ml (p=0.02).
Conclusion: There was a significant difference seen in the levels of SPB and a trend toward increased levels of SPC with increasing ages of tissue controls. SPB levels are comparable between controls and AP animals. SPC levels were significantly higher in AP animals compared to controls. These data suggest that the artificial placenta promotes type 2 pneumocyte maturity.
