An autopsy study of atherosclerosis in aorta, common carotid arteries and circle of Willis.

The incidence, extent and degree of atherosclerosis was studied in descending aorta, common carotid arteries and circle of Willis obtained from 50 cadavers above the age of 30 years. Specimens were stained grossly with Sudan IV and the total atherosclerotic area was measured and atherosclerotic index was calculated. The co-efficient of correlation between extent of atherosclerosis with age and nutritional status was calculated. The incidence of atherosclerosis was 100.0% in the aorta and common carotid arteries in all the specimens. In case of circle of Willis, it was 76.5% in the fourth decade and 87.5% in the fifth decade, rising to 100.0% thereafter. The atherosclerotic index increased with age at all the three locations. However, at any given age, the atherosclerotic index in circle of Willis was much less as compared to the aorta or common carotid arteries. The most prominent lesion in all the three groups of vessels in the fourth and fifth decades was the presence of a fatty streak. There was a sudden spurt in the extent of fibrous plaques in the aorta, carotid arteries and circle of Willis in the sixth decade. Complicated lesions also appeared in this decade, and became more marked after sixty years of age. The correlation between the extent and degree of atherosclerosis with age was found to be highly significant statistically (p < 0.001). A significant correlation (p < 0.001) was also found between the nutritional status and extent and degree of atherosclerosis. No conclusion could be derived regarding differences in the extent and degree of the disease in the two sexes.