Comparison of oscillatory wall shear stress in the abdominal aorta of men and women: relationship to abdominal aortic aneurysm (AAA) development

Background Numerous animal and human studies have confirmed a relationship between inflammation, wall shear stress (WSS, the frictional force of fluid felt at a vessel wall) and vascular pathologies. These studies suggest the importance of WSS as a predictive factor in evaluating an individual’s risk of developing vascular disease. There have been several observational studies which indicate that men are four times more likely to develop abdominal aortic aneurysm (AAA) than women. Based on the known link between oscillatory WSS and aneurysm dilation, we conducted a study to investigate differences in the WSS patterns in the abdominal aortas of men and women. We utilized a method of measuring WSS which combines an analytical solution to the Navier-Stokes equations and phase contrast magnetic resonance (PCMR) derived flow waveforms. The hypothesis was that women would have a lower values of pro-inflammatory oscillatory WSS than men.