Title: Extent of Vascular Damage at Varying Degrees of Stretch in Hypoxic Neonatal Brachial Plexus
Abstract: In complex birthing scenarios, the brachial plexus (BP) nerves may be overstretched with additional complications of hypoxia. Characterizing extent of vascular damage in hypoxic neonatal BP at varying degrees of stretch can further our understanding of BP injury thresholds. All procedures were approved by Institutional Animal Care and Use Committee. Eleven neonatal piglets (3-5 days old) were anesthetized and exposed to FiO2 of 7% for 1 hour to induce hypoxia and re-perfused to FiO2 of 21%. BP nerves were exposed and stretched at a rate of 500 mm/min to predetermined low (<15%) and high (>15%) strains. Post-stretch, BP nerves were harvested and OCT-embedded. Ten-µm-thick serial longitudinal sections were stained with Hematoxylin-Eosin. Using Olympus BX53 motorized microscope, stained slides were imaged at 10x magnification along nerve length. Using a custom MATLAB script, each stitched image was split into regions of interest (ROI). An independent-blinded observer scored each ROI for vascular damage on a scale of 0-2 (0-no damage, 1-torn vessel, 2-scattered blood cells). Preliminary results show vascular damage increases with increasing stretch and similar degrees of damage were observed in central and peripheral regions.
Abstract: In complex birthing scenarios, the brachial plexus (BP) nerves may be overstretched with additional complications of hypoxia. Characterizing extent of vascular damage in hypoxic neonatal BP at varying degrees of stretch can further our understanding of BP injury thresholds. All procedures were approved by Institutional Animal Care and Use Committee. Eleven neonatal piglets (3-5 days old) were anesthetized and exposed to FiO2 of 7% for 1 hour to induce hypoxia and re-perfused to FiO2 of 21%. BP nerves were exposed and stretched at a rate of 500 mm/min to predetermined low (<15%) and high (>15%) strains. Post-stretch, BP nerves were harvested and OCT-embedded. Ten-µm-thick serial longitudinal sections were stained with Hematoxylin-Eosin. Using Olympus BX53 motorized microscope, stained slides were imaged at 10x magnification along nerve length. Using a custom MATLAB script, each stitched image was split into regions of interest (ROI). An independent-blinded observer scored each ROI for vascular damage on a scale of 0-2 (0-no damage, 1-torn vessel, 2-scattered blood cells). Preliminary results show vascular damage increases with increasing stretch and similar degrees of damage were observed in central and peripheral regions.