The histopathological characteristics of the newly formed blood vessels in the atherosclerotic intima of human coronary arteries examined three-dimensionally and light microscopically using serial sections were as follows : (1) the vascular density in atherosclerotic intimas significantly correlated with the degree of luminal stenosis, (2) the neovascularization was prominent in the intimas showing chronic inflammatory infiltrate, formation of granulation tissue or atheromatous change, while decreased in the extensively hyalinized and calcified intimas, and (3) the intimal vasculature originated mainly from the adventitia and partly from the proper coronary lumen. These findings support the hypothesis that the arteriointimal angiogenesis represents an essential and coincidental response to arterial injuries occurring in atherosclerotic process.
In vivo introduction of human VEGF mRNA into rabbit carotid arteries using HVJ-liposome method induced the prominent angiomatoid proliferation of endothelial cells in thickened intima due to fibromuscular hyperplasia. Thus, the interventional suppression of intimal neovascularization by gene therapy may be an effective therapy for the restenosis following PTCA in the futural perspectives.