Epidemiology of iatrogenic vertebral artery injury in cervical spine surgery: 21 multicenter studies

METHODS We performed a retrospective, multicenter study involving clinical and radiological evaluations for IVAI. We included all CSS between 2012 and 2016, and excluded neck-mass excision and pain intervention. We collected data about patient characteristics and complications, including diagnosis, surgical technique, and the presence of IVAI. In IVAI cases, the technique details, characteristics, and sequelae were investigated.

RESULTS In total, 14,722 patients, with 15,582 CSS in 21 centers, were included; IVAIs were identified in 13 (0.08%) patients. Surgery-specific incidence of IVAI was 1.35% in cases involving C1-2 posterior fixation and 0.20% in cases involving C3-6 posterior fixation. Common injury mechanisms were screw-in (31%) and high-speed drilling (23%). Screw-related IVAI occurred in nine (69%) patients, and IVAI of the C1 lateral-mass and C2 pedicle screws occurred in four and three patients, respectively. Among the 13 cases of IVAI, three (23%) involved cerebellar or stem infarction; the infarction had no substantial correlation with injury grade or dominancy.

CONCLUSIONS Overall incidence of IVAI in CSS was 0.08%. C1-2 posterior fixation had the highest incidence of IVAI at 1.35%. Although clinical results of IVAI can be highly variable, controlling the risk factors of IVAI is important.