[Chronic dissecting aneurysm of the aorta].

Three observations (2 males, aged 44 and 63, and a female of 47) of chronic dissecting aortic aneurysms are described. In all the cases the patients didn't die immediately from the acute dissection, as the blood accumulated in the canal formed, broke back into the aortic lumen, thus a lower orifice of the chronic aneurysm was formed. It might be possible that in some aortic dissections the hematomas fused, forming subsequently a canal. The new canal joined the main trunk (the aorta) by 2 or 3 orifices. The duration of the dissection was not identified clearly, but the canals formed were in all cases organized and had a smooth inner surface. Histology revealed striate-like necroses in the aortic wall, as well as fragmentation, swelling and lysis of the elastic fibers, resulting in the formation of slits, cavities with accumulation of metachromatic substances, i. e. the changes, characteristic for the medianecrosis (Gsell-Erdheim syndrome). A possible primary injuring effect of xenobiotics on the aortic wall is suggested.