Prevalence and anatomy of anomalous left vertebral artery originated from aorta evaluated by computed tomographic angiography.

PURPOSE

We evaluated anatomical characteristics and clinical significance of left vertebral artery (VA) originating from aortic arch (AA) by computed tomography (CT) angiography.

METHODS

CT angiography was performed in 3460 patients between March 01, 2014 and November 30, 2015. We examined course of prevertebral VA (PVVA) segment and level of entry into the cervical vertebra transverse foramen (CVTF) of left VA originated from AA.

RESULTS

One hundred fifty-three of 3460 patients had left VA originated from AA. Six of 153 patients had dual origin of VA. Entry level to CVTF of 156 left VAs in 153 cases ranged from C3 to C6. Entry level to CVTF of 156 right VAs in 153 cases ranged from C3 to C7. One hundred fifty-six right PVVA segments positioned in longus colli muscle lateral side in 112 VAs, longus colli muscle anterior surface near longus colli muscle lateral margin in 41 VAs, and unknown location in three VAs. One hundred fifty-six left PVVA segments positioned in anterior surface of longus colli muscle midline in 5 cases, anterior surface of longus colli muscle near longus colli lateral margin in 138 cases, longus colli muscle lateral side in 12 cases, and anterior surface of anterior scalene muscle midline in one case.

CONCLUSIONS

Left VA may arise from the AA. If a long PVVA segment entering higher CVTF is present, operator can perform anterior cervical surgery via contralateral approach for avoidance of VA injury.