title: Do abdominal aortic aneurysm necks increase in size faster after endovascular than open repair?
abstract: BACKGROUND
  Progression of aneurysmal disease in the aortic neck poses a threat to durable abdominal aortic aneurysm (AAA) repair. We tested the hypothesis that 2 years after AAA repair the size of the aortic neck increased more after endovascular (EVAR) than open repair.
  
  
  METHODS
  For a subset of EVAR 1 trial patients, true outer-wall area at three levels of the aortic neck was measured using a Vitrea2 workstation, and rate of change over 2 years analysed.
  
  
  RESULTS
  The 67 EVAR patients and 56 open repair patients were well-matched, very similar to the total EVAR 1 cohort. The mean area change over 2 years at the superior mesenteric artery was small for both groups. However at the caudal renal artery (CRA), adjusted regression coefficient was 0.68 cm(2)/y greater after EVAR (p<0.001) and 0.77 cm(2)/y at a level 15 mm distal to it (p<0.001). The area at the CRA of 45 available post-procedure scans showed a large proportion of the increase had occurred by 3 months (mean 4.8 cm(2) to 5.9 cm(2) versus 6.7 cm(2) at 2 years).
  
  
  CONCLUSIONS
  The increase in aortic neck size was much greater 2 years after EVAR versus open repair. Further research is ongoing to establish whether the dilatation is progressive after stent-graft placement.
authors.affiliation: Vascular Surgical Research Group, Imperial College at Charing Cross Hospital, St Dunstan's Road, London W6 8RP, UK. a.rodway@imperial.ac.uk
authors.forename: A D
authors.initials: AD
authors.lastname: Rodway
authors.forename: J T
authors.initials: JT
authors.lastname: Powell
authors.forename: L C
authors.initials: LC
authors.lastname: Brown
authors.forename: R M
authors.initials: RM
authors.lastname: Greenhalgh
mesh_terms: D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D001027:Aortography / Q000379:methods; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D004108:Dilatation, Pathologic; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D011857:Radiographic Image Interpretation, Computer-Assisted; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure