title: Does the diameter of abdominal aortic aneurysm influence late survival following abdominal aortic aneurysm repair? A systematic review and meta-analysis.
abstract: BACKGROUND
  Studies reporting the influence of preoperative abdominal aortic aneurysm diameter on late survival following abdominal aortic aneurysm repair have not been consistent.
  
  
  OBJECTIVE
  To report the influence of abdominal aortic aneurysm diameter on overall long-term survival following abdominal aortic aneurysm repair.
  
  
  METHODS
  Embase, Medline and the Cochrane electronic databases were searched to identify articles reporting the influence of abdominal aortic aneurysm diameter on late survival following open aneurysm repair and endovascular aneurysm repair published up to April 2015. Data were extracted from multivariate analysis; estimated risks were expressed as hazard ratio.
  
  
  RESULTS
  A total of 2167 titles/abstracts were retrieved, of which 76 studies were fully assessed; 19 studies reporting on 22,104 patients were included. Preoperative larger abdominal aortic aneurysm size was associated with a worse survival compared to smaller aneurysms with a pooled hazard ratio of 1.14 (95% CI: 1.09-1.18), per 1 cm increase in abdominal aortic aneurysm diameter. Subgroup analysis of the different types of repair was performed and the hazard ratio (95% CI), for open aneurysm repair and endovascular aneurysm repair were 1.08 (1.03-1.12) and 1.20 (1.15-1.25), respectively, per 1 cm increase. There was a significant difference between the groups p < 0.02.
  
  
  CONCLUSIONS
  This meta-analysis suggests that preoperative large abdominal aortic aneurysm independently influences overall late survival following abdominal aortic aneurysm repair, and this association was greater in abdominal aortic aneurysm repaired with endovascular aneurysm repair.
authors.affiliation: Department of Surgery, University of Otago, Christchurch, New Zealand manar.khashram@gmail.com.|Department of Vascular Endovascular & Transplant Surgery, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Manar
authors.initials: M
authors.lastname: Khashram
authors.affiliation: Department of Population Health, University of Otago, Christchurch, New Zealand.
authors.forename: Phil N
authors.initials: PN
authors.lastname: Hider
authors.affiliation: Department of Population Health, University of Otago, Christchurch, New Zealand.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Williman
authors.affiliation: Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Jones
authors.affiliation: Department of Vascular Endovascular & Transplant Surgery, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Roake
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000401:mortality; D016009:Chi-Square Distribution; D057510:Endovascular Procedures / Q000009:adverse effects / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011183:Postoperative Complications / Q000401:mortality; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: Abdominal aortic aneurysm; endovascular aneurysm repair; hazard rates; size; survival factors; systematic review