Arteriogenesis: A natural arteriolar bypass in occlusive cardiovascular diseases. The role of mast cells

Occlusive cardiovascular diseases are the leading course of death worldwide. Although surgical revascularization remains to be the treatment of choice for most patients, therapeutic promotion of arteriolar bypass presents an alternative to patients in which surgical intervention is not possible. The presence of pre-existing collateral network in the human heart and essentially in every organ, form the basis of recirculation of blood flow after stenosis of the main supply artery. The remodelling and enlargement of inner diameter of the interconnecting arterioles due to significant arterial occlusion is referred to as Arteriogenesis. Sufficient collateral enlargement can allow significant blood flow bypassing the stenosed segment of an artery to prevent distal tissue ischemia, such as in coronary artery diseases and chronic lower limb ischemia. Several experimental studies showed the putative role of leukocytes, especially monocytes, which extravasate, releases growth factors and degrading enzymes in the vicinity of the growing collateral arterioles. Despite the promising experimental animal studies to stimulate arteriogenesis, many large-scale clinical trials have yielded disappointing results in humans with no or limited success. Here I present the novel concept of arteriogenesis, its milestones in the scientific world and the contribution of mast cells as new players in arteriogenesis.