The vasa vasorum (VV) — “vessels on vessels” — are blood vessels that lie on the outside of arteries. VV develop as arteries thicken to ensure the entire artery is supplied with sufficient nutrients. Multiple hypotheses suggest the VV may play a role in the causation or progression of atherosclerosis.

In this 2017 article, surgeon Axel Haverich argues that surgical and clinical observations — both his own and those of his colleagues — are more consistent with a view of atherosclerosis as “an adventitial microvessel disease” than the traditional understanding of atherosclerosis as a response to injury and/or inflammation in the arterial endothelium.