[Data on ultrasonographic anatomy of precanal segment of the vertebral artery]

Described in the article are the results of using ultrasonographic duplex scanning for studying anatomical peculiarities of the precanal segment of the human vertebral artery.

Ultrasonographic duplex scanning (USDS) of the extracranial portions of brachiocephalic vessels was performed in a total of 215 inpatients without haemodynamically significant stenoses of the arteries of the vertebrobasilar basin. The patients found to have pathological alterations in the vertebrobasilar basin were excluded from the examined group. We studied the first segment of the vertebral artery from the origin to its entry into the canal of the transverse processes of cervical vertebrae (V1 segment according to the ultrasonographic nomenclature). We measured the diameter of the vertebral artery, assessing the pattern the vessel's passage, presence of pathological tortuosity, topographic interrelations between the V1 segment of the vertebral artery and structures of the neck, as well as analysing age-specific alterations in the anatomy of the vertebral artery.

By means of duplex scanning we in a non-invasive manner managed to gain a deeper insight into the anatomical peculiarities of the passage and structure of the initial portion of the human vertebral artery, as well as the differences in the structure between the contralateral vertebral arteries. We determined the average values of the diameters of the vertebral artery, its area, topographical relationships with the surrounding anatomical reference points along the length of the precanal segment, available for visualization by this method of study, and age-related peculiarities of the anatomy of the vertebral artery.

Ultrasonographic duplex scanning of the extracranial portions of brachiocephalic vessels in humans is an effective, available and accurate technique making it possible to assess the anatomy of the initial portion of the vertebral artery. The average values of the diameters and area of the transverse section of the left vertebral artery turned out to be significantly greater than similar values of the right vertebral artery in the overwhelming majority of cases. Due to structural peculiarities of the aortic arch branches, in particular, independent origin of the left subclavian artery from the aortic arch, the left vertebral artery has, as a rule, greater length than the right one and differs by the topographical correlations with the surrounding structures on the neck, which is confirmed by the ultrasonographic method of study. The ultrasonographic method of study makes it possible to sufficiently effectively assess the difference in depth of the passage of the trunk of the vertebral artery in tissues of the fascial spaces of the neck in representatives of various types of the body-build. We also revealed a tendency towards a tortuous passage of the vertebral artery in the precanal segment in 35-44% of cases irrespective of the body-build, age and gender.