title: Does the Traversing Length of the Aorta Change After Closing Wedge Osteotomy for Ankylosing Spondylitis Patients With Thoracolumbar Kyphosis?: A Magnetic Resonance Imaging Investigation.
abstract: METHODS
  A prospective magnetic resonance imaging (MRI) study.
  
  
  OBJECTIVE
  To investigate the change in aortic traversing length in patients with thoracolumbar kyphosis secondary to ankylosing spondylitis (AS) after closing wedge osteotomy (CWO).
  
  
  BACKGROUND
  The CWO has been widely adopted for the correction of thoracolumbar kyphosis caused by AS. During this procedure, the aorta may be elongated in the instrumented area, which implies a potential risk of the aortic injury. To date, no reports have been specifically published using MRI to investigate the alteration in aortic traversing length in patients with AS undergoing CWO.
  
  
  METHODS
  From June 2013 to July 2015, 24 patients with AS with thoracolumbar kyphosis with a mean age of 38.1 years were recruited in the present study. All patients underwent single-level CWO. MRI examinations were performed before and 2 weeks after surgery. For each subject, the aortic diameter and length were measured on the MRI. Radiographic measurements included the global kyphosis, thoracic kyphosis, lumbar lordosis, local kyhosis, angle of fusion levels, and anterior height of the osteotomized vertebra. The height of these patients was also recorded.
  
  
  RESULTS
  The aortic traversing length significantly increased by an average of 2.0 cm after surgery. Significant changes in height, global kyphosis, lumbar lordosis, local kyphosis, and angle of fusion levels were observed (P < 0.01), whereas the anterior height of the osteotomized vertebra was comparable before and after surgery (P > 0.05). In addition, the correlation analysis revealed a significant correlation between the aortic traversing length and changes in global kyphosis, lumbar lordosis, local kyphosis, angle of fusion levels, and height (P < 0.01).
  
  
  CONCLUSIONS
  The stretch of the aorta after CWO for the correction of thoracolumbar kyphosis was quantitatively verified by MRI investigation in the present study. Spine surgeons should be aware of the potential vulnerability of aortic injury in patients with AS undergoing CWO.
  
  
  METHODS
  4.
authors.affiliation: Department of Spine Surgery, Drum Tower Clinical Medical College of Nanjing Medical University, Nanjing, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Bang-Ping
authors.initials: BP
authors.lastname: Qian
authors.affiliation: Department of Spine Surgery, Drum Tower Clinical Medical College of Nanjing Medical University, Nanjing, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Department of Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Sai-Hu
authors.initials: SH
authors.lastname: Mao
authors.affiliation: Department of Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Qu
authors.affiliation: Department of Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Ze-Zhang
authors.initials: ZZ
authors.lastname: Zhu
mesh_terms: D000328:Adult; D001011:Aorta / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging* / Q000601:surgery; D008141:Lordosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods; D011446:Prospective Studies; D013167:Spondylitis, Ankylosing / Q000000981:diagnostic imaging* / Q000601:surgery; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D055815:Young Adult