Gender-Related Differences in Iliofemoral Arterial Anatomy among Abdominal Aortic Aneurysm Patients

Background: Gender-related differences in iliofemoral anatomy are critically important for delivery of modern EVAR devices, however remains poorly characterized in the context of other patient-specific factors. The goal of the present study was to provide a detailed quantification of anatomic differences in iliofemoral anatomy between genders while controlling for height, weight, and vascular comorbidities. Methods: Fifty women with computed tomography angiograms for evaluation of abdominal aortic aneurysm between 2000 and 2012 were selected and matched to an equal nonpaired cohort of males with similar age, body mass indices (BMIs), and prevalence of vascular comorbidities (e.g., coronary artery disease, peripheral vascular disease). A 3-dimensional workstation was used to measure outer and inner diameters at anatomic reference locations at the common iliac (CIA), external iliac (EIA), and common femoral (CFA) arteries. Iliac aneurysms were excluded from analysis. Multivariate analysis-of-covariance models were employed for evaluating CIA, EIA, and CFA diameters as dependent variables. Results: Luminal diameters were significantly smaller at the CIA (8.8 vs. 11.8 mm, P < 0.001), EIA (7.0 vs. 8.4 mm, P < 0.001), and CFA (6.7 vs. 9.5 mm, P < 0.001) arteries between men and women despite similar BMIs (27.7 vs. 27.5, P = 0.20). Similar statistically significant differences were found between men and women when comparing adventitial diameters (P < 0.001), however not when comparing degrees of stenosis (defined as outer diameter minus inner diameter [P = 0.96]). Female gender was negatively correlated with luminal diameter at the CIA (-2.34 [-3.72 to -0.96]; coef. [95% CI]), EIA (-0.95 [-1.8 to -0.04]), and CFA (-2.61 [-3.51 to -1.71]) arteries. Weight (per 10 kg) was positively correlated with luminal diameters measured at the CIA (0.41 [0.12-0.68]) and CFA (0.35 [0.16-0.53]). No independent relationships between height, vascular comorbidities, and arterial diameters were identified. 24% (n = 12) of females compared to only 14% (n = 7) of males in this study would have been ineligible for EVAR with current devices due to poor iliac access criteria. Conclusions: Women have significantly smaller iliofemoral arterial systems compared to men, even after controlling for height, weight, and other comorbidities that are known to affect vascular anatomy. This quantifiable difference in arterial anatomy is important to consider when deciding between various open versus endovascular treatment strategies for women.