Poster 37: Temporal Evaluation of the Vascular Network after Traumatic Brain Injury

The role of the cerebrovascular network and its acute response to traumatic brain injury (TBI) is poorly defined and emerging evidence suggests that cerebrovascular reactivity is altered. We explored how cortical vessels are physically altered from 1 to 30 days post injury (dpi) following TBI using a newly developed technique, vessel painting. Design(s): We tested our hypothesis that a focal moderate TBI results in decrements to structural aspects of the vasculature, followed by restoration and maturation of new vessels at the impact site. Rats underwent a moderate controlled cortical impact and were compared to sham operated animals. Animals underwent vessel painting perfusion to label the entire cerebral vasculature at 1, 3, 7, 14, and 30 dpi followed by whole brain axial and coronal imaging using a wide-field fluorescence microscope. Setting(s): Not applicable Participants: Not applicable Interventions: Not applicable Main Outcome Measure(s): Not applicable Results: Cortical vessel network characteristics were analyzed for classical angiographic features (junctions, density, lengths) of axial images wherein we observed significant (P < .05) reductions in vessel junctions and vessel density of the injured hemisphere at 1 and 3 dpi. Biological complexity can be quantified using fractal geometric features where we observed that fractal measures (kurtosis, skew-ness) were also reduced significantly (P < .05) in the early time points with evidence of vessel proliferation and maturation at later time points. Similar findings are noted on coronal imaging and analysis. Conclusion(s): Acutely after TBI there is a reduction in vascular network and vascular complexity, followed by proliferation and maturation of vasculature at the impact site. These findings provide structural evidence for the hemodynamic alterations that have been reported in rodents and patients after TBI.