Abstract 1004: Three-dimensional Characterization Of Sex Differences In Abdominal Aortic Aneurysm Progression Via Vascular Deformation Mapping

Introduction: Although Abdominal Aortic Aneurysms (AAA) are more common in men, women are at greater risk for AAA growth and rupture. Vascular deformation mapping (VDM) is a novel technique that utilizes deformable image registration to qualify and quantify three-dimensions (3D) AAA growth using routing clinical computed tomography angiogram (CTA) images. Hypothesis: We hypothesize that females will have higher rates of focal AAA growth when compared to males. Aims: In this study we aimed to leverage VDM to investigate sex differences in AAA growth. Methods: We identified patients with infra-renal AAA and ≥2 CTA from 2010-2021. Patients with non-contrast CT scans or poor image quality were excluded. Propensity score matching was used to identify a cohort of males and females matched on age, hypertension, and smoking history. AAA were segmented and VDM was conducted using a multi-step image registration of aortic CTA studies to generate a deformation field which is then used to quantify 3D AAA growth rate (GR). Patient characteristics, maximum diameter (Dmax), AAA volume (Vmax), and GR were obtained. Statistical shape modeling was utilized to compare average 3D growth patterns between males and females. Results: Seventeen male and females with AAA were matched. There was no differences between sexes in race, diabetes, symptomatic status, or repair. Males had a trend toward larger Dmax (4.9 ± 0.6 vs 4.5 ± 0.6 cm, p = 0.055) and had Vmax at baseline (118.7 ± 69.9 vs 76.6 ± 35.0 cm 3 , p = 0.034). There was no difference between sexes when looking at change in Dmax or Vmax. Male and female AAA had no difference in average GR (0.11 ± 0.08 vs 0.17 ± 0.22 cm/year, p = 0.293). Shape models demonstrated more diffuse AAA growth for males and more eccentric AAA growth for females (Figure 1). Conclusions: Despite comparable changes in Dmax, Vmax, and GR, women demonstrated a more eccentric distribution of AAA growth, a finding which may contribute to higher rupture risk in women.