title: Anomalous vertebral and posterior communicating arteries as a risk factor in instrumentation of the posterior cervical spine.
abstract: 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.
authors.affiliation: Hokkaido University Hospital, Department of Orthopaedic Surgery, North-15, West-7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nagahama
authors.forename: H
authors.initials: H
authors.lastname: Sudo
authors.forename: K
authors.initials: K
authors.lastname: Abumi
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Takahata
authors.forename: S
authors.initials: S
authors.lastname: Hiratsuka
authors.forename: K
authors.initials: K
authors.lastname: Kuroki
authors.forename: N
authors.initials: N
authors.lastname: Iwasaki
mesh_terms: D000015:Abnormalities, Multiple / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001268:Atlanto-Axial Joint / Q000002:abnormalities; D002574:Cervical Vertebrae / Q000002:abnormalities / Q000601:surgery*; D002941:Circle of Willis / Q000002:abnormalities* / Q000000981:diagnostic imaging; D003097:Collateral Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods; D012307:Risk Factors; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation; D014057:Tomography, X-Ray Computed; D014711:Vertebral Artery / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000293:injuries; D014715:Vertebrobasilar Insufficiency / Q000150:complications; D055815:Young Adult
keywords: Algorithm; Cervical instrumentation surgery; Posterior communicating artery; Risk factor; Three-dimensional CT angiography; Vertebral artery