[Anatomic pathological aspects of chronic obliterating arteriopathies of the extremities (author's transl)].

It appears that the classical concept of atherosclerosis cannot be applied indiscriminately to all cases and that it is essentially valid for the aorta and its large branches of predominantly elastic structure. When more peripheral arterial trunks are considered, those of muscular type, the lesions are in great part characterized by a dystrophic fibrosis of the media, associated with a diffuse intimal thickening and with stratified fibro-hyaline plaques narrowing the lumen; the latter are responsible for the circulatory insufficiency and gangrene. Comparative analysis of 50 surgical specimens allow us to conclude that those fibro-hyaline plaques represent progressively stratified parietal thrombi that are populated by myocytes, at the contact of which ultrastructural investigation reveals important phenomena of elastogenesis and elastolysis. Most probably, the myocytes originate from the media, through fenestration within the inner elastic membrane. These facts have more than just a purely speculative interest: they express the great plasticity of the arterial walls and their capacity of adaptation to new hemodynamic and biologic conditions. It is interesting to note that this lesion constantly presents signs of metabolic activity and structural remodeling despite its long standing caracter.