Microsurgical Anatomy of the Third Segment of the Vertebral Artery and the Suboccipital Region

[Objective]To accumulate the morphological data and provide the basis of microvascular anatomy for clinical treatment.[Methods]Fifteen adult cadaver heads(30 sides) were used in the study. The morphology of the vertebral arteries was observed and their dimensions measured with the aid of an operating microscope.[Results]The third segments of the vertebral arteries were tortuous. The external diameters of left vertebral arteries (4.16±0.62)mm were larger than the right ones (3.72±0.38) mm. The length of the third segment of the vertebral artery was (55.77±10.02)mm, while the length of the occipital artery was (86.51±11.06)mm.[Conclusion]The third segment of the vertebral artery is tortuous to enable the movements of the neck. Lateral approach is often used to expose the third segment of the vertebral artery. Anatomy marks are important in the suboccipital region operations.