Vasa Vasorum and Atherosclerosis of Coronary Arteries

Vasa vasorum (»vessels of the vessel«) are arterioles, capillaries and venules that nourish large arteries and veins. They are derived either from the main blood vessel itself in the case of arteries, and for veins from adjacent arteries as venous vasa vasorum. Atherosclerosis is a sys­temic dysfunctional endothelial, chronic inflammatory, fibro-proliferative, prothrombotic, angiogenic, multifactorial disease of the arterial intima caused by the retention of modified low-density lipoproteins, along with hemodynamic and redox stress. The first condition for the development of atherosclerosis involves high LDL cholesterol blood levels. The infiltra­tion, retention and modification of excess LDL cholesterol in the arterial intima cause the induction of endothelial cells and consecutive migration of leukocytes into the subendothelial space. Macrophages and lymphocytes inside the arterial intima cause inflammation and tis­sue damage. A plaque forms, and the thickening of the intima leads to hypoxia and consecutive angiogenesis. Newly formed vasa vasorum destabilize the plaque and cause progression of atherosclerosis. An unstable plaque can rupture and this is strongly associated with vascu­lar occlusion, myocardial ischemia, and infarction. However, vasa vasorum play a positive role when it comes to the regression of atherosclerosis as they may provide a pathway for the removal of intimal fat. Many questions are raised about the best treatment for atherosclerosis. The beneficial effects of statins have already been proven, while other attractive future treatments comprise power­ful immunosuppressive and antiinflammatory agents, therapeutic angiogenesis and anti- -angiogenesis. Finally, vaccination is also an attractive approach to induce protective immunity.