Abstract 489: Peak Wall Stress and Rupture Risk of Abdominal Aortic Aneurysms Are Not Influenced by Age
OBJECTIVES: Older patients with Abdominal Aortic Aneurysms (AAA) face higher perioperative mortality and, according to a recent meta-analysis, a higher risk of rupture. The relationship between age and AAA biomechanics, however, has not been studied previously. Our aim was to investigate age dependent differences in peak wall stress (PWS) and peak wall rupture risk (PWRR = wall stress / wall strength), as estimated by finite element modeling (FEM).
METHODS: 80 patients, 52-88 years old with AAA diameters between 40 and 60 mm, who had undergone computed tomography angiography (CT-A), were included. PWS and PWRR were estimated, by FEM, based on patient demographics and CT-A-derived AAA geometry, including the intraluminal thrombus (ILT). Three diameter matched age groups (≤65, 66-75 and ≥76 years old) were compared with respect to ILT-volume, PWS and PWRR with ANOVA and Kruskal-Wallis test. Correlation was tested with Spearman’s rank correlation coefficient.
RESULTS: All age groups had similar diameters (53.2 vs 52.8 vs 54.6 mm, P=0.44). No associations between age and biomechanical parameters were found. Differences in PWS (200.9 vs 199.0 vs 198.3 kPa, P=0.98) and PWRR (0.39 vs 0.37 vs 0.38 P=0.74) between age groups were small and non-significant. No correlation existed between age and PWS (r=0.018, P=0.88) or PWRR (r=0.031, P = 0.78). In the whole cohort, women had a significantly higher PWRR than men had (0.48 vs 0.35, P<0.0001).
CONCLUSIONS: Biomechanical parameters estimated by FEM do not differ between different age groups. However, as previously shown, women have a higher rupture risk which may explain the correlation between age and risk of rupture found in recent studies, since more women are found in the higher age groups.
Author Disclosures: M. Lindquist Liljeqvist: None. R. Hultgren: None. C. Gasser: None. J. Roy: None.
- © 2014 by American Heart Association, Inc.