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:
A vascularised fibular strut graft was used for anterior spinal fusion in 16 patients with spinal kyphosis. The procedure was abandoned in three because of difficulty in establishing a vascular anastomosis and in one because the grafted fibula dislodged two days after operation. One patient died after five days. Of the 11 remaining patients, there were seven males and four females. Their ages at the time of operation averaged 30.9 years (12 to 71). The number of vertebrae fused averaged 6.7 (5 to 9) and the length of fibula grafted averaged 10.9 cm (6.5 to 18). Average follow-up was 54 months (27 to 84). Bone union occurred at both ends of the grafted fibula in all 11 patients, with an average time to union of 5.5 months (3 to 8). We did not see a fracture of the grafted fibula. Two patients had postoperative complications; the graft dislodged in one and laryngeal oedema occurred two days after operation in the other. A vascularised fibular strut graft provides a biomechanically stable and long-standing support in spinal fusion because the weak phase of creeping substitution does not take place in the graft.
