Comparative morphology of the internal elastic lamina of cerebral and peripheral arteries

Atherosclerosis progresses later and with fewer complicated plaques in cerebral arteries than in peripheral arteries. The internal elastic lamina has been proposed to be important for the migration of smooth muscle cells into the intima during intimal thickening and atherosclerosis.

A total of 280 segments were retrieved from 14 autopsy specimens. Five sites were selected for analysis in each case: the middle cerebral artery, basilar artery, coronary artery, iliac artery and renal artery. We investigated the differences in the internal elastic lamina of cerebral and peripheral arteries.

The average thickness of the internal elastic lamina of the cerebral arteries was larger than that of the peripheral arteries in both the early and advanced atherosclerotic plaque groups. Among the cerebral arteries, the basilar arteries had a thicker internal elastic lamina than the middle cerebral arteries. Among the peripheral arteries, the renal arteries had the thickest internal elastic lamina, followed by the iliac arteries and coronary arteries. Atherosclerosis led to a reduction in the thickness of the internal elastic lamina of the basilar, middle cerebral, and renal arteries. The stratification of the internal elastic lamina of iliac arteries significantly affected its measurement. The internal elastic lamina of coronary arteries was not affected by atherosclerosis, but it appeared fragmented.

The results suggest that the characteristics of atherosclerotic plaques in cerebral and peripheral arteries may be related to the characteristics of the internal elastic lamina.