title: Vertebral artery injuries in cervical spine surgery.
abstract: BACKGROUND
  Vertebral artery injuries (VAIs) are rare but serious complications of cervical spine surgery, with the potential to cause catastrophic bleeding, permanent neurologic impairment, and even death. The present literature regarding incidence of this complication largely comprises a single surgeon or small multicenter case series.
  
  
  OBJECTIVE
  We sought to gather a large sample of high-volume surgeons to adequately characterize the incidence and risk factors for VAI, management strategies used, and patient outcomes after VAI.
  
  
  METHODS
  The study was constructed as a cross-sectional study comprising all cervical spine patients operated on by the members of the international Cervical Spine Research Society (CSRS).
  
  
  METHODS
  All patients who have undergone cervical spine surgery by a current member of CSRS as of the spring of 2012.
  
  
  METHODS
  For each surgeon surveyed, we collected self-reported measures to include the number of cervical cases performed in the surgeon's career, the number of VAIs encountered, the stage of the case during which the injury occurred, the management strategies used, and the overall patient outcome after injury.
  
  
  METHODS
  An anonymous 10-question web-based survey was distributed to the members of the CSRS. Statistical analysis was performed using Student t tests for numerical outcomes and chi-squared analysis for categorical variables.
  
  
  RESULTS
  One hundred forty-one CSRS members (of 195 total, 72%) responded to the survey, accounting for a total of 163,324 cervical spine surgeries performed. The overall incidence of VAI was 0.07% (111/163,324). Posterior instrumentation of the upper cervical spine (32.4%), anterior corpectomy (23.4%), and posterior exposure of the cervical spine (11.7%) were the most common stages of the case to result in an injury to the vertebral artery. Discectomy (9%) and anterior exposure of the spine (7.2%) were also common time points for an arterial injury. One-fifth (22/111) of all VAI involved an anomalous course of the vertebral artery. The most common management of VAI was by direct tamponade. The outcomes of VAIs included no permanent sequelae in 90% of patients, permanent neurologic sequelae in 5.5%, and death in 4.5%. Surgeons at academic and private centers had nearly identical rates of VAIs. However, surgeons who had performed 300 or fewer cervical spine surgeries in their career had a VAI incidence of 0.33% compared with 0.06% in those with greater than 300 lifetime cases (p=.028).
  
  
  CONCLUSIONS
  The overall incidence of VAI during cervical spine surgery reported from this survey was 0.07%. Less experienced surgeons had a higher rate of VAI compared with their more experienced peers. The results of VAI are highly variable, resulting in no permanent harm most of the time; however, permanent neurologic injury or death occur in 10% of cases.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA. Electronic address: lunardini20@gmail.com.
authors.forename: David J
authors.initials: DJ
authors.lastname: Lunardini
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Eskander
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA.
authors.forename: Jesse L
authors.initials: JL
authors.lastname: Even
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Dunlap
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA.
authors.forename: Antonia F
authors.initials: AF
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA.
authors.forename: Joon Y
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Ward
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA.
authors.forename: James D
authors.initials: JD
authors.lastname: Kang
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Kaufmann Medical Building, 3471 Fifth Ave., Pittsburgh, PA 15213, USA.
authors.forename: William F
authors.initials: WF
authors.lastname: Donaldson
mesh_terms: D002574:Cervical Vertebrae / Q000601:surgery*; D003430:Cross-Sectional Studies; D019299:Decompression, Surgical / Q000009:adverse effects; D017586:Diskectomy / Q000009:adverse effects; D059526:Foraminotomy / Q000009:adverse effects; D006801:Humans; D015994:Incidence; D007796:Laminectomy / Q000009:adverse effects; D019637:Orthopedic Procedures / Q000009:adverse effects*; D012307:Risk Factors; D013122:Spinal Diseases / Q000601:surgery*; D011795:Surveys and Questionnaires; D057772:Vascular System Injuries / Q000209:etiology*; D014711:Vertebral Artery / Q000002:abnormalities / Q000293:injuries*
keywords: Cervical spine; Complications; Surgery; Vertebral artery injury