Objective To explore the morphological symmetry of the anterior circulation cerebral arteries based on digital subtraction angiography(DSA),and to analyze the value of arterial walking route on the healthy side in guiding catheterization in endovascular treatment for patients with sick-side major artery occlusion of the anterior circulation.Methods A total of 250 consecutive patients who underwent cerebral angiography at the Shengli Oilfield Central Hospital of China between January 2021 and August 2022 were enrolled in this study as angiography group,which was subdivided into youth angiography subgroup(＜50 years),middle-aged angiography subgroup(50-69 years),and elderly angiography subgroup(≥70 years).Other 170 patients with acute occlusion of the anterior circulation vessels,who received emergency mechanical thrombectomy,were collected as thrombectomy group.After successful recanalization,the cerebral angiographic imaging findings of both groups,including the arterial walking route symmetry of bilateral C1 segment,C2-C3 segment,ophthalmic segment,M1 segment proximal to the bifurcation,and M1 segment distal to the bifurcation,were analyzed and compared between the two groups.The recanalization rate and the consistency of bilateral arterial walking route in the thrombectomy group were also analyzed.Results No statistically significant differences in the arterial walking route of the C1 segment,C2-C3 segment,ophthalmic segment,M1 segment proximal to the bifurcation,and M1 segment distal to the bifurcation existed between the left side and right side(all P＞0.05).Ordinary bilateral symmetry was observed in M1 segment proximal to the bifurcation,and excellent bilateral symmetry was observed in all the other segments.There were no statistically significant differences in the bilateral arterial walking route of the C1 segment,C2-C3 segment,ophthalmic segment,M1 segment proximal to the bifurcation,and M1 segment distal to the bifurcation between each other among the three subgroups(all P＞0.05).Ordinary bilateral symmetry of the C1 segment was observed in the youth angiography subgroup,ordinary bilateral symmetry of the M1 segment proximal to the bifurcation was observed in all three subgroups,and excellent bilateral symmetry was observed in all the other segments.In the thrombectomy group the recanalization rate was 95.5％and the consistency rate of bilateral arterial walking route was 89.0％.Conclusion Bilateral symmetry exists in the C1 segment,C2-C3 segment,ophthalmic segment,M1 segment proximal to the bifurcation,and M1 segment distal to the bifurcation of the anterior circulation cerebral arteries.These findings provide a reliable basis of referring healthy-side arterial walking route to guide catheterization in endovascular treatment for mechanical thrombectomy and recanalization of sick-side major artery occlusion of the anterior circulation.(J Intervent Radiol,2024,33:472-478)