Importance of preoperative detection of vertebral artery anomalies in neck surgery

Objectives: The objective of this study were to examine the course of the vertebral artery (VA) and define VA anomalies important for neck surgery using three-dimensional computer tomography (3D CT). Study Design: Thee design used was an observational study with retrospective 3D CT angiography analysis. Methods: Four hundred VAs depicted on 200 3D CT angiographies were analysed to determine the relationship between the extraosseous portions of the VA to the neck organs, with special emphasis on the thyroid gland area, the artery of origin of the VA and the entrance/exit locations of its foraminal segment. Results: Twenty-three out of 400 VAs were anomalous (5.75%). These anomalies were found in 18 patients, unilaterally in 13 in bilaterally five. The level of entrance was abnormal in all cases; it was at C3 in 4.3% (n= 1), at C4 in 17.4% (n= 4), at C5 in 74% (n= 17) and at C7 in 4.3% (n= 1). The VA ran close to the thyroid gland in eight cases (34.8%) even touching the lower pole (17.4%; n= 4) or the upper pole (8.7%; n= 2) of the gland. The anomalous VA crossed the common carotid artery and the internal jugular vein by a way of a median loop in eight cases (34.8%). Conclusion: In planning neck or spinal surgery, the surgeon should bear in mind that VA anomalies are present in approximately 5.5-6.5% of cases. Preoperative 3D CT allows precise identification of anomalous VAs, thereby reducing the possible risk of intraoperative injury.