title: Expansion rates of abdominal aortic aneurysm: current limitations in evaluation.
abstract: OBJECTIVE
  Literature on the expansion rate of infrarenal aortic aneurysm is scant. This review was carried out to assess whether there is a normal rate of expansion for infrarenal aortic aneurysms.
  
  
  METHODS
  Review of literature relating to abdominal aortic aneurysm (AAA) measurement and expansion rates. Articles were identified from a search of the computerised Medline database from 1966 onwards.
  
  
  RESULTS
  Nine studies produced expansion rates for 3.0-5.0 cm AAA ranging from 0.17 to 0.57 cm per year. Evaluation of these studies showed that they are not wholly comparable in terms of source population, sample size, disease definition and period of assessment.
  
  
  CONCLUSIONS
  It is not possible to discuss with confidence the "normal" expansion rate of infrarenal aortic aneurysms at any diameter. To elucidate fully the behaviour of AAA, a clear and universal definition of AAA is required in order that it may be used within a large, multicentered prospective cohort study.
authors.affiliation: Department of Vascular Surgery, Royal Infirmary of Edinburgh, U.K.
authors.forename: K A
authors.initials: KA
authors.lastname: Wilson
authors.forename: K R
authors.initials: KR
authors.lastname: Woodburn
authors.forename: C V
authors.initials: CV
authors.lastname: Ruckley
authors.forename: F G
authors.initials: FG
authors.lastname: Fowkes
mesh_terms: D017542:Aneurysm, Ruptured / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D017544:Aortic Aneurysm, Abdominal / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D015982:Bias; D018450:Disease Progression; D006801:Humans; D018579:Patient Selection; D015995:Prevalence; D012107:Research Design; D012307:Risk Factors; D012422:Rupture, Spontaneous