a1 Departments of Mechanical and Aerospace Engineering and Bioengineering, University of California San Diego, La Jolla, CA 92093-0411, USA
Abdominal aortic aneurysm (AAA), a common vascular disease among the adult population, forms in the portion of the aorta below the renal arteries and upstream of its bifurcation into the two iliac arteries. While the precise cause of this vascular disease is still unknown, it is believed to be multi-factorial and predominantly degenerative, arising through a complex interplay among several biological factors as well as from specific local changes in the haemodynamic stresses on the vessel's wall. Using a simple mechanical model to simulate the difference in the stiffness of the aorta and iliac arteries, Duclaux, Gallaire & Clanet (J. Fluid Mech., 2010, this issue, vol. 664, pp. 5–32) propose a scaling argument for the transition between homogeneous and inhomogeneous deformation of an elastic tubular membrane that offers a plausible explanation for the observed localization of the AAAs. While neglecting long-term tissue remodelling and other important biological processes, the fluid mechanics model of Duclaux et al. (2010) appears to be consistent with some known associated risk factors.