[Angiogenesis and arteriogenesis; the long road from concept to clinical application]

In patients with obstructive artery disease, two different forms of compensatory vessel growth occur; angiogenesis and arteriogenesis. Angiogenesis is the formation of a capillary network, through the activation and proliferation of endothelial cells in ischaemic tissue. Arteriogenesis is the transformation of pre-existent collateral arterioles into functional collateral arteries. Circulating blood cells, especially monocytes, play an important role in the arteriogenesis process. Animal experiments have demonstrated that local treatment with monocyte chemoattractant protein-1 results in an elevated accumulation of monocytes/macrophages and an increased growth of collateral vessels. The stimulation of arteriogenesis will probably result in a greater increase in blood flow to the ischaemic tissue, than the stimulation of angiogenesis. This can be explained by the difference in diameter between the collateral vessels formed in arteriogenesis and the capillaries formed in angiogenesis. Research to the efficacy of growth factors that stimulate the arteriogenesis process is still at an experimental stage. The stimulation of arteriogenesis is studied in models of both peripheral and coronary obstructive disease.