Introduction: Evaluation of angiogenesis and neovascularization in stroke has been limited to measurements of vascular density and identification of newly formed vessels. However, structural aspects of the configuration of those new vessels have not been studied. We investigated structural features of micro neovascularization in an animal model of cerebral ischemia.
Methods: We used a mice model of ischemia and synangiosis. In essence, C57/BL6J mice underwent MCA ligation via a temporal craniotomy, the temporalis muscle was apposed to the ischemic brain and animals were sacrificed after 4 weeks. CD31-stained vasculature was evaluated by confocal microscopy. Images were analyzed using Fiji’s Skeleton and Direction tools. Vessel directionality was assessed as the proportion of vessels running along the predominant vector direction. Branching pattern was quantified as the junction points per vessel.
Results: Vascular density was increased on the experimental side (CD31+: 7.17% vs. 5.13%, p < 0.01), consistent with neovascularization. On the experimental side, increased parallelism of the vessels was observed (14% vs. 8% p = 0.01), and reduced branching (control-experimental= 0.027+/- 0.01 p = 0.001), as expected for more immature vessels.
Conclusion: Increased parallelism and reduced branching are structural features of neovascularization after ischemia-revascularization in this model. Future studies including different time-points could clarify the evolution of these changes.