Using the electron microscope, the authors examined the structure of the wall in a case of arteriomegaly of the inferior mesenteric artery in man. Structural changes concerned the elastic material showing signs of degeneration. Based on a comparison with literary findings, the authors conclude that tortuosity of the arteries, aneurysms and arteriomegaly are caused by congenital, age-dependent and pathological changes in the elastic material in the vessel wall. There exist basic structural differences in the arterial wall in arteriomegaly and in atherosclerosis.

Department of Cardiovascular and Respiratory Sciences University La Sapienza Rome Italy