title: Extent of aortic coverage and incidence of spinal cord ischemia after thoracic endovascular aneurysm repair.
abstract: BACKGROUND
  Risk factors for spinal cord ischemia (SCI) after thoracic endovascular aneurysm repair (TEVAR) remain unclear. Aortic coverage was examined as a risk factor for SCI using quantitative three-dimensional computed tomography angiography (CTA) analysis.
  
  
  METHODS
  The medical records, radiographic imaging studies, and a prospectively maintained database of all TEVAR procedures performed during a 7-year period were retrospectively reviewed. Preoperative anatomic dimensions and postoperative graft path lengths were measured from CTAs using curved planar and orthogonal multiplanar reformations along centerline paths. SCI was defined as transient or permanent lower extremity neurologic deficit without associated intracerebral hemispheric events.
  
  
  RESULTS
  Of 326 TEVAR cases, 241 patients (74%) had satisfactory imaging. Thirty-three (10%) had SCI. These patients were older (72.7 +/- 10.6 vs 64.7 +/- 15.8 years, p = 0.005) and had longer intraoperative procedure times (137 +/- 65 vs 113 +/- 68 minutes, p = 0.05). Despite similar total lengths of native thoracic aorta (295.0 +/- 36.3 vs 283.1 +/- 39.8 mm, p = 0.17), patients with permanent SCI had a greater absolute (260.5 +/- 40.9 vs 195.8 +/- 81.6 mm, p = 0.002) and proportionate (88.8% +/- 12.1% vs 67.6% +/- 24.0%, p = 0.001) length of aortic coverage. The average length of uncovered aorta proximal to the celiac artery in patients with SCI was 17.3 +/- 21.8 mm vs 63.1 +/- 62.9 mm in patients without SCI (p = 0.0006). Neither the patency of the hypogastric arteries nor left subclavian artery was associated with SCI.
  
  
  CONCLUSIONS
  The extent and distal location (relative to the celiac artery) of aortic coverage were associated with an increased risk of SCI. Prophylactic measures for spinal cord protection should be considered in patients whose thoracic aortas require extensive coverage.
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, University of Florida, Gainesville, Florida, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Feezor
authors.forename: Tomas D
authors.initials: TD
authors.lastname: Martin
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Hess
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Daniels
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Beaver
authors.forename: Charles T
authors.initials: CT
authors.lastname: Klodell
authors.forename: W Anthony
authors.initials: WA
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D000792:Angiography / Q000379:methods; D017130:Angioplasty / Q000009:adverse effects* / Q000379:methods; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D015994:Incidence; D007430:Intraoperative Care / Q000379:methods*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D020760:Spinal Cord Ischemia / Q000453:epidemiology / Q000503:physiopathology / Q000517:prevention & control*; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome