Comparative morphology of the hepatic and coronary artery walls. Part I. Differences in the distribution and intensity of non-atherosclerotic intimal thickening and atherosclerosis.

We compared the morphology of the hepatic artery intima which is free of atherosclerosis, with that of the typically atherosclerosis-prone coronary artery. The study group comprised material collected from 116 autopsies. Subjects were aged between 1 month and 90 years. Specimens were collected from grossly normal arterial segments. An already known fact was confirmed: the presence and remarkable intensity of non-atherosclerotic intimal thickening in the coronary arteries since the beginning of life. On the contrary, hepatic artery intimal thickening was incidental during the first 4 decades of life and regular later on. During all the decades intimal thickness was decreased in the hepatic artery in comparison to the coronary artery. Initial atherosclerosis was noted during the 4th decade of life in the coronary artery and during the 8th and 9th decades in the hepatic artery. Intimal thickness was always lower in women compared to men. These findings reveal a positive correlation between the intensity of intimal hyperplasia and the incidence of atherosclerosis. The intimal pattern is of limited value in the determination of an unidentified subject age who underwent an autopsy. The thickness of the hepatic artery intima, which surpasses 200 microns indicates that the subject is at least 40 years of age, while initial atherosclerosis--the 8th or 9th decades of life.

Comparative morphology of the hepatic and coronary artery walls. Part II. The relation between the internal elastic membrane, non-atherosclerotic intimal thickening and atherosclerosis.

Evident difference in the occurrence of atherosclerosis between hepatic and coronary arteries justifies the search for local preconditions of this disease. In this study we compared the internal elastic membrane morphology of both arteries. It appeared to be mono- or polylinear (laminar) and continuous in the hepatic artery. This was in contrast to its fragmentation in the coronary artery since the beginning of life. Thus, the condition of the internal elastic membrane may play an important role in the development of non-atherosclerotic intimal thickening. Continuous elastica could make the migration of medial myocytes into the intima more difficult (hepatic artery). On the other hand, fragmented coronary artery elastica seems to facilitate this migration. In turn, intimal thickening is less or more advanced, respectively.

Comparative morphology of the hepatic and coronary artery walls. Part III. The insignificance of medial morphologic features in the determination of an autopsied unidentified subjects age.

Since hepatic arteries are free of atherosclerosis any possible wall structure change may be attributed to age. We determined the media of hepatic and coronary arteries in view of this assumption. We measured its thickness and myocytic density (per 1 mm2 of cross-section) from specimens collected from autopsied subjects, aged up to 90 years. The media gradually thickens with age, although values noted during particular decades remain statistically insignificant. The myocytic density (in 1 mm2) was almost constant throughout life. The latter observation is incompatible, in comparison with data reported by other authors (diminution was expected).