Three-dimensional Imaging Study Of V1 Segment Variation Of Vertebral Artery

Objective:To study the abnormal condition of V1 segment of vertebral artery by three-dimensional imaging of CTA in the upper chest of head and neck,and to explore the relationship between the starting position of vertebral artery and the height of the vertebral artery passing through the transverse foramen of cervical vertebra.Methods:The imaging data of 480 patients who underwent CTA examination in the Department of Neurosurgery,Second Hospital of Hebei Medical University from March 2017 to March 2019 were analyzed retrospectively.The original CTA images of the head and neck were transmitted to the image post-processing workstation,and the bone and blood vessels of the head and neck were reconstructed three-dimensionally.The origin position,course and height of the bilateral vertebral arteries passing through the cervical transverse foramen were observed,and the variation rates of the left and right vertebral arteries were compared.For those with normal origin of right vertebral artery,they were divided into C4,C5 and C6 groups according to the height of passing through the transverse foramen of cervical vertebra.Ten patients in each group were randomly selected.The distance from the starting position of right vertebral artery to the starting position of right common carotid artery(L1)and the distance from right thyroid trunk(L2)were measured respectively,and the relative position of the starting position of vertebral artery was calculated by L1/(L1+L2)×100%.To analyze the abnormal origin of left and right vertebral arteries,the incidence of abnormal height of transverse foramen of cervical vertebra and the difference of variation of left and right vertebral arteries.To explore the relationship between the origin of vertebral artery and the height of vertebral artery passing through the transverse foramen of cervical vertebra,and to analyze the causes of abnormal vertebral artery from the origin of vertebral artery embryo,and to explore the influence of abnormal origin and height of vertebral artery passing through the transverse foramen of cervical vertebra on clinical diagnosis and treatment of craniocerebral diseases.Results:1.Among 480 patients,457 cases of bilateral vertebral artery originated from subclavian artery,and the incidence rate was 95.2%.Another 23 cases had abnormal origin of vertebral artery,the incidence rate was 4.8%,of which19 cases originated from aortic arch and 1 case originated from left external carotid artery.The right vertebral artery originated from the right common carotid artery in 3 cases,and all of them were complicated with vagal right subclavian artery.Comparing the incidence of abnormal origin of left and right vertebral artery,the difference was statistically significant(χ~2=12.874,P<0.001).It can be considered that the incidence of abnormal origin of left vertebral artery is higher than that of right vertebral artery.2.Among 480 cases,405 cases of bilateral vertebral artery passed through C6 transverse foramen,the incidence rate was 84.4%;In the other 75cases,the height of vertebral artery passing through the transverse foramen of cervical vertebra was abnormal,the incidence rate was 15.6%,among which34 cases on the left side passed through the transverse foramen of C3,C4,C5and C7 respectively in 1,4,24 and 4 cases,and 1 case directly entered the foramen magnum.In 41 cases on the right side,1,14 and 26 cases passed through the transverse foramen C3,C4 and C5 respectively.Comparing the incidence of abnormal height of the left and right vertebral artery passing through the cervical transverse foramen,there was no significant difference(χ~2=0.937,P=0.199).It can be concluded that the incidence of abnormal height of the left vertebral artery passing through the cervical transverse foramen has no significant difference with the right one.3.Among the patients with normal origin of vertebral artery,there were15 cases with normal origin of left vertebral artery and abnormal height of left vertebral artery passing through cervical transverse foramen,the incidence rate was 3.26%(15/460),and 38 cases with normal origin of right vertebral artery and abnormal height of right vertebral artery passing through cervical transverse foramen,the incidence rate was 7.97%(38/477).Comparing the incidence of normal origin of left and right vertebral artery with abnormal height of passing through cervical transverse foramen,the difference was statistically significant(χ~2=9.717,P=0.01).It can be considered that the incidence of abnormal height of passing through cervical transverse foramen of right vertebral artery is higher than that of left vertebral artery when the origin of vertebral artery is normal.4.Among the patients with abnormal origin of the left vertebral artery,the proportion of the left vertebral artery originated from the aortic arch was the highest(19/20),and the height of the left vertebral artery passing through the transverse foramen of cervical vertebra was abnormal(18/19).Only one vertebral artery passed through the transverse foramen of C6 cervical vertebra normally.Among the patients with abnormal origin of the right vertebral artery,the right vertebral artery originated from the right common carotid artery(3/3),and all of them were accompanied by vagal right subclavian artery(3/3),and the height of the right vertebral artery passing through the cervical transverse process hole was abnormal(3/3).Compare that incidence of abnormal origin of vertebral artery with abnormal height through cervical transverse foramen,the difference was statistically significant(χ~2=252.45,p<0.001).it can be concluded that the incidence of abnormal origin of vertebral artery with abnormal height through cervical transverse foramen is significantly higher than that of normal origin of vertebral artery with abnormal height through cervical transverse foramen.5.Among the patients with normal origin of vertebral artery,96.7%(445/460)of the left vertebral artery passed through the transverse foramen of cervical vertebra,and 92.0%(439/477)of the right vertebral artery passed through the transverse foramen of cervical vertebra.Comparing the relative position of the origin of the right vertebral artery among the three groups,the difference was statistically significant:[C4:(24.3±2.1)%,C5:(47.9±6.6)%,C6:(77.7±1.7)%,H=20.178,P<0.001].However,the closer to the right thyroid trunk artery,the lower the height of the cervical transverse process hole.Conclusions:There is a close correlation between the starting position of vertebral artery and the height of penetrating through the transverse process hole of cervical vertebra.When the initial position of vertebral artery is abnormal,the height of vertebral artery passing through the transverse process hole of cervical vertebra is mostly abnormal.The closer the initial relative position of the right vertebral artery with normal origin is to the right common carotid artery,the higher the height of passing through the transverse process hole of cervical spine.The closer to the right thyroid trunk,the lower the height of the cervical transverse process hole.The incidence of abnormal origin of left vertebral artery was higher than that of right vertebral artery.There was no significant difference in the incidence of abnormal height of left vertebral artery passing through the transverse foramen of cervical spine compared with right vertebral artery.When the origin of vertebral artery is normal,the incidence of abnormal height of right vertebral artery passing through the transverse foramen of cervical vertebra is higher than that of left vertebral artery.This study summarizes the abnormal situation of vertebral artery V1 segment,which improves clinicians’understanding of vertebral artery anatomy.It is helpful to make a reasonable operation plan to make clear the abnormal origin and course of vertebral artery before operation;At the same time,abnormal vertebral artery can also explain the causes of some cerebrovascular diseases.Therefore,it is of great significance for clinical practice to fully understand the abnormal origin and course of vertebral artery and the relationship between them.