Analysis of expansion patterns in 4-4.9 cm abdominal aortic aneurysms.
Our objective was to analyze the growth pattern of 4-4.9 cm infrarenal abdominal aortic aneurysms (AAAs). We used an observational, longitudinal, prospective study design. We followed 4-4.9 cm AAAs with 6-monthly abdominal computed tomographic (CT) scans (January 1988-August 2004). AAA growth was defined as an increase in aortic diameter > or =2 mm in each surveillance period. We established the aortic expansion pattern in AAA with three or more CT scans as continuous, discontinuous. The latter includes at least one period of nongrowth (<2 mm/6 months). We studied the influence of cardiovascular risk factors (CVRFs), comorbidity, and AAA anatomical characteristics using the chi-squared test, t-test, life tables, and Kaplan-Meier for statistical analysis. We included 195 patients: 183 (93.8%) men, age 71 +/- 8.3 years (50-90). The follow-up period was 50 +/- 36.4 months (6.5-193.7). The growth pattern (n =131) was continuous in 15 (11.5%) and discontinuous in 116 (88.5%) AAA. The mean expansion rate was higher in AAAs with continuous expansion (7.92 +/- 3.74 vs. 2.74 +/- 2.94 mm/year, p < 0.0001). No CVRFs or comorbidity influenced the expansion pattern (p > 0.05). The eccentric thrombus was associated with a greater incidence of continuous growth (p = 0.05), with no influence of aortic calcification (p > 0.1). The expansion of 4-4.9 cm AAA is mostly irregular and unpredictable. We have not found any modifiable risk factors which influence their growth pattern. The eccentric distribution of the thrombus is associated with continuous expansion.
Vega de Céniga
M
M
Department of Angiology and Vascular Surgery, Hospital de Galdakao-Usansolo, Barrio Labeaga S/N, 48960 Galdakao-Usansolo (Bizkaia), Spain. mvega@hgda.osakidetza.net
Gómez
R
R
Estallo
L
L
de la Fuente
N
N
Viviens
B
B
Barba
A
A
D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*; D001027:Aortography / Q000379:methods; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed