Localization and sequence of development of atherosclerotic lesions in the carotid and vertebral arteries.

The distribution of fatty streaks, fibrous plaques, complicated lesions, and calcified lesions were determined for each of five segments in the common carotid arteries, each of five segments of internal carotid arteries, and for each of seven segments of vertebral arteries in specimens from 961 autopsied cases in Oslo, Norway, and Guatemala. The pattern of distribution of the lesions along the length of the arteries is characteristic for the different arteries. This pattern seems to be independent of sex, age group, type of lesions, and geographic location. Fatty streaks and fibrous plaques have the same pattern of distribution within each artery at all ages. This close topographic association is consistent with the hypothesis that fibrous plaques are derived from fatty streaks. The early atherosclerotic lesions are located at the same sites where stenotic and occlusive lesions have been reported. Thus, it is likely that the early atherosclerotic lesions and the stenotic or occlusive lesions are pathogenetically closely associated with each other.