title: Change of aortic length after closing-opening wedge osteotomy for patients with ankylosing spondylitis with thoracolumbar kyphosis: a computed tomographic study.
abstract: METHODS
  A computed tomographic study.
  
  
  OBJECTIVE
  To investigate the change in aortic length in patients with ankylosing spondylitis (AS) with thoracolumbar kyphosis after closing-opening wedge osteotomy (COWO).
  
  
  BACKGROUND
  Several previous studies reported that COWO can effectively correct severe thoracolumbar kyphosis caused by AS. However, one disadvantage of COWO is elongation of the aorta, which increases the risk of aortic injury. To date, no studies have analyzed the alteration in aortic length in patients with AS undergoing COWO for thoracolumbar kyphosis.
  
  
  METHODS
  A total of 21 consecutive patients with AS with a mean age of 38.9 years undergoing COWO for the correction of thoracolumbar kyphosis were retrospectively studied. Radiographical measurements included global kyphosis, thoracic kyphosis, lumbar lordosis, angle of fusion levels, local kyphosis, and anterior height of the osteotomized vertebra. The computed tomographic scans of the spine were used to measure the aortic diameter (at the site of the osteotomy) and length (the length between the superior endplate of the upper instrumented vertebra and the inferior endplate of L4).
  
  
  RESULTS
  The aortic length increased by an average of 2.2 cm postoperatively. Significant changes in global kyphosis, local kyphosis, angle of fusion levels, lumbar lordosis, anterior height of the osteotomized vertebra, and aortic diameter at the site of the osteotomy were observed (P < 0.01). Significant correlation was noted between aortic length and changes in global kyphosis (r = 0.525, P = 0.015), local kyphosis (r = 0.654, P = 0.001), angle of fusion levels (r = 0.634, P = 0.002), and lumbar lordosis (r = 0.538, P = 0.012).
  
  
  CONCLUSIONS
  Aortic lengthening after COWO for correction of kyphosis was quantitatively confirmed by this study. Spine surgeons should be aware of the potential risk for the development of aortic injury in patients with AS undergoing COWO for the correction of thoracolumbar kyphosis.
  
  
  METHODS
  4.
authors.affiliation: From the Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Ming-Liang
authors.initials: ML
authors.lastname: Ji
authors.forename: Bang-ping
authors.initials: BP
authors.lastname: Qian
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Ze-zhang
authors.initials: ZZ
authors.lastname: Zhu
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
mesh_terms: D000328:Adult; D001011:Aorta / Q000473:pathology*; D001018:Aortic Diseases / Q000000981:diagnostic imaging / Q000209:etiology; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000209:etiology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods*; D017063:Outcome Assessment, Health Care / Q000379:methods; D012189:Retrospective Studies; D013167:Spondylitis, Ankylosing / Q000150:complications / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult