[New aspects in the pathologic anatomy of arteriosclerosis obliterans].

The pathogenetic notion of arteriosclerosis and the clinical syndrome of the arterial obstructive diseases are not identical, but interfere in different points which are discussed in detail. Arteriosclerotic changes must be delimitated from pure age-conditioned changes of the arteries, since the two are sufficiently defined and deviate from each other in important characteristics. Only the so-called fibrous thickening of the intima is still doubtful concerning its classification. For the understanding of the severe obliterating arteriosclerosis the knowledge of the early stages is necessary. The disease begins with focal proliferations of smooth muscle cells and a disturbance of permeability of the arterial endothelium. The two cell forms are discussed more in detail and estimated in its significance for the vascular disease. Particularly the lesion of the endothelium nowadays plays an increasing role as causative factor for the development of an arteriosclerosis, since already simple increases of permeability via and edema of the intima may lead to an accumulation of lipoproteins in the vascular wall, also when the lipid level in blood is not increased. At present in clinical practice often the question of the delimitation of an obliterating arteriosclerosis from other arteriopathies leading to a vascular obstruction arises. Since a part of these diseases is to be diagnosed by biopsies of the arteries, the histological differential diagnosis of the most important inflammatory arterial diseases is discussed.