[Topographical and anatomical characteristics of the vertebral artery in the third segment]

Lesions of the vertebral arteries (VAs) are encountered in clinical practice comparatively often. They can be manifested by a wide range of signs and symptoms, including transitory ischaemic attacks in the vertebrobasilar basin, ischaemic strokes (IS), and chronic insufficiency of cerebral circulation with the transition into vascular encephalopathy. Surgical management of VA proximal stenoses requires that the surgeon be highly qualified, because it is associated with a high rate of both intra- and postoperative complications (amounting to 10-15%), including ischaemic strokes, thrombosis of the reconstruction zone, haemorrhage, lymphocele, as well as lesions of thephrenic, recurrent, and sympathetic nerves. Therefore, intervention by means of endovascular techniques is currently the main method of treating proximal stenoses of the VA. Along with it, in the presence of tortuosity and loop formations of the VA, surgical intervention on the first segment (VI) of the VA is the only possible option of treatment thereof However, reconstruction of the distal portion of the VA due to complexity of manipulations in the area involved is the least frequently performed operative intervention. The present work deals with the findings obtained in studying the surgical anatomy of the VA in its third segment (V3). in order to determine the variants of the artery's location and possibilities of surgical treatment in arterial pathology in the first (VI) and second (V2) segments. Autopsy was performed on 15 cervical fragments from patients 30 VAs, respectively) having died from causes not associated with cerebrovascular insufficiency. In the dorsal position of the head, we measured the diameter and length of the VA in the spaces between the first and second cervical vertebrae (M +/- m = 4.6 +/- 1.2 mm and 16.4 +/- 1.7 mm, respectively) and between the first cervical vertebra and the edge of the occipital foramen (M +/- m = 4.4 +/- 1.1 mm and 14.7 +/- 2.2 mm, respectively), the diameter of the vertebral canal in the first cervical vertebra (M +/- m = 5.85 +/- 1.1 mm), the presence of the cerebrospinal branches (in 12%), the distance between the transverse processes of the first and second cervical vertebrae (M +/- m = 15.95 +/- 1.05 mm), as well as the distance between the first cervical vertebra and the edge of the occipital foramen (M +/- m = 13.05 +/- 2.5 mm). The average value of the arterial intima thickness amounted to 68.4 +/- 6.3 microm. Noted was a moderate increase in the arterial wall thickness on the left (485.15 +/- 35.35 microm) as compared with that of the right VA (416.25 +/- 1l3.42 microm) (P = 0.12), at the expense of the middle tunic and adventitia. Hence, the most favourable site for surgical management of the VA pathology is the space between the transverse processes of the first and second cervical vertebrae, in which the diameter of the vertebral canal makes it possible to increase the arterial diameter up to 5 mm, while the length and thickness of the wall--to mobilize the artery without resection of the transverse processes, and to adequately establish an anastomosis in order to determine the variants of the artery's location and possibilities of surgical treatment in arterial pathology in the first (VI) and second (V2) segments. Autopsy was performed on 15 cervical fragments from patients 30 VAs, respectively) having died from causes not associated with cerebrovascular insufficiency. In the dorsal position of the head, we measured the diameter and length of the VA in the spaces between the first and second cervical vertebrae (M +/- m = 4.6 +/- 1.2 mm and 16.4 +/- 1.7 mm, respectively) and between the first cervical vertebra and the edge of the occipital foramen (M +/- m = 4.4 +/- 1.1 mm and 14.7 +/- 2.2 mm, respectively), the diameter of the vertebral canal in the first cervical vertebra (M +/- m = 5.85 +/- 1.1 mm), the presence of the cerebrospinal branches (in 12%), the distance between the transverse processes of the first and second cervical vertebrae (M +/- m = 15.95 +/- 1.05 mm), as well as the distance between the first cervical vertebra and the edge of the occipital foramen (M +/- m = 13.05 +/- 2.5 mm). The average value of the arterial intima thickness amounted to 68.4 +/- 6.3 microm. Noted was a moderate increase in the arterial wall thickness on the left (485.15 +/- 35.35 microm) as compared with that of the right VA (416.25-1l3.42 microm) (P = 0.12), at the expense of the middle tunic and adventitia. Hence, the most favourable site for surgical management of the VA pathology is the space between the transverse processes of the first and second cervical vertebrae, in which the diameter of the vertebral canal makes it possible to increase the arterial diameter up to 5 mm, while the length and thickness of the wall--to mobilize the artery without resection of the transverse processes, and to adequately establish an anastomosis.