The trend of indirect anastomosis formation in a 2-vessel occlusion plus encephalo-myo-synangiosis rat model

BACKGROUND: Basic research on the factors influencing indirect anastomosis formation in a 2-vessel occlusion plus encephalo-myo-synangiosis (2VO + EMS) rat model is conducive to improving the efficacy of indirect revascularization surgery in the clinic. However, the time point at which anastomosis between the rat temporal muscle (TM) and brain naturally has the greatest effect after encephalo-myo-synangiosis (EMS) remains unknown. Therefore, we conducted this study to explore the peak time of indirect anastomosis formation in the 2VO + EMS rat model. METHODS: Forty 2VO + EMS rats were randomly divided into five groups (n=8) according to the length of time (by week) after EMS, and 2VO rats were used as the control group (n=8). The expression of vascular endothelial growth factor (VEGF) and CD31 on the EMS side of the brain, perfusion ratio [improvement of cerebral blood perfusion (CBP) on the EMS side] and Morris water maze (MWM) results were compared between groups. Furthermore, the trends of the above variables were explored over weeks. RESULTS: Overall, the expression of VEGF and CD31, the perfusion ratio and the cognitive improvement in the 2VO + EMS rat model gradually increased over weeks after EMS. The VEGF and CD31 expression (as detected by immunofluorescence), perfusion ratio and number of times crossing the platform area peaked at 4 weeks after EMS. In addition, both the escape latency and the time spent in the target quadrant peaked in the fifth week after EMS. CONCLUSIONS: After establishing the 2VO + EMS rat model, the degree of endothelial cell (EC) proliferation and CBP improvement on the EMS side of the brain peaked at 4 weeks after EMS, whereas the cognitive improvement peaked in the fifth week.