We investigated the incidence of anomalies in
the vertebral arteries and Circle of Willis with three-dimensional
CT angiography in 55 consecutive patients who had undergone an instrumented
posterior fusion of the cervical spine. We recorded any peri-operative and post-operative complications.
The frequency of congenital anomalies was 30.9%, abnormal vertebral
artery blood flow was 58.2% and vertebral artery dominance 40%. The posterior communicating artery was occluded on one side in
41.8% of patients and bilaterally in 38.2%. Variations in the vertebral
arteries and Circle of Willis were not significantly related to
the presence or absence of posterior communicating arteries. Importantly,
18.2% of patients showed characteristic variations in the Circle
of Willis with unilateral vertebral artery stenosis or a dominant
vertebral artery, indicating that injury may cause lethal complications.
One patient had post-operative cerebellar symptoms due to intra-operative
injury of the vertebral artery, and one underwent a different surgical
procedure because of insufficient collateral circulation. Pre-operative assessment of the vertebral arteries and Circle
of Willis is essential if a posterior spinal fusion with instrumentation
is to be carried out safely. Cite this article:
