Structure and function of vasa vasorum.

Vasa vasorum provide an important source of nutrition to arteries and veins. In normal arteries, vasa vasorum from the adventitia grow into the media of large arteries and veins and actively regulate blood flow to the wall of these vessels. In atherosclerotic arteries, vasa vasorum proliferate into the intima-media, where they provide nutrition to the thickened artery. These neovascular channels are thin-walled, however, and may contribute to intraplaque hemorrhage, plaque disruption, and mural thrombosis.