title: Growth rate and associated factors in small abdominal aortic aneurysms.
abstract: OBJECTIVE
  To study the growth rate and factors influencing progression of small infrarenal abdominal aortic aneurysms (AAA).
  
  
  METHODS
  Observational, longitudinal, prospective study.
  
  
  METHODS
  We followed patients with AAA <5 cm in diameter in two groups. Group I (AAA 3-3.9 cm, n = 246) underwent annual ultrasound scans. Group II (AAA 4-4.9 cm, n = 106) underwent 6-monthly CT scans.
  
  
  RESULTS
  We included 352 patients (333 men and 19 women) followed for a mean of 55.2+/-37.4 months (6.3-199.8). The mean growth rate was significantly greater in group II (4.72+/-5.93 vs. 2.07+/-3.23 mm/year; p<0.0001). Group II had a greater percentage of patients with rapid aneurysm expansion (>4 mm/year) (36.8 vs. 13.8%; p<0.0001). The classical cardiovascular risk factors did not influence the AAA growth rate in group I. Chronic limb ischemia was associated with slower expansion (< or = 4 mm/year) (OR 0.47; CI 95% 0.22-0.99; p = 0.045). Diabetic patients in group II had a significantly smaller mean AAA growth rate than non-diabetics (1.69+/-3.51 vs. 5.22+/-6.11 mm/year; p = 0.032).
  
  
  CONCLUSIONS
  The expansion rate of small AAA increases with the AAA size. AAA with a diameter of 3-3.9 cm expand slowly, and they are very unlikely to require surgical repair in 5 years. Many 4-4.9 cm AAA can be expected to reach a surgical size in the first 2 years of follow-up. Chronic limb ischemia and diabetes are associated with reduced aneurysm growth rates.
authors.affiliation: Department of Angiology and Vascular Surgery, Hospital de Galdakao, Barrio Labeaga S/N, 48960 Galdakao (Bizkaia), Spain. mvega@hgda.osakidetza.net
authors.forename: M
authors.initials: M
authors.lastname: Vega de Céniga
authors.forename: R
authors.initials: R
authors.lastname: Gómez
authors.forename: L
authors.initials: L
authors.lastname: Estallo
authors.forename: L
authors.initials: L
authors.lastname: Rodríguez
authors.forename: M
authors.initials: M
authors.lastname: Baquer
authors.forename: A
authors.initials: A
authors.lastname: Barba
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000453:epidemiology / Q000503:physiopathology*; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007511:Ischemia / Q000453:epidemiology; D007866:Leg / Q000098:blood supply; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors