[The prevalence of atherosclerotic lesions in the aortic arch]

In relation to the aortic arch operation, atherosclerotic lesions in this area was investigated in autopsy specimen. Fifty specimens of the aorta with severe atherosclerotic lesions were chosen from 182 autopsies of patients older than 70 years at Tenri Hospital. The aortic arch and the adjacent aorta were divided into 9 segments (three portions around orifices of the arch tributaries [1-3], the ascending aorta proximal to the branchiocephalic artery [4], the descending aorta distal to the left subclavian artery [5], and 4 portions of the aortic arch which consisted with proximal anterior [6], distal anterior [7], proximal posterior [8], and distal posterior wall [9]) as shown in the figure. The degree of atherosclerosis was scored by Gore-Tejada atherosclerosis index (ASCI). The ASCI of the arch (12.7) was significantly higher than the ascending aorta (5.3). (p > 0.05). Among 9 segments of the aortic arch, the ASCIs of the anterior wall of the distal arch (25.1), the aorta distal to the left subclavian artery (17.3), the arch around the orifice of the brachiocephalic artery (17.1) were significantly higher. The ulcerative plaques were predominantly found at the anterior wall of the distal arch (36%). On the other hand, the calcified plaques were predominantly found around the orifice of the brachiocephalic artery (26%). Ten specimens demonstrated significant stenosis at the orifice of the left subclavian artery. From this autopsy study, the degree of atherosclerotic lesion was predominant at the anterior wall of the distal aortic arch and at around the orifice of the brachiocephalic artery.(ABSTRACT TRUNCATED AT 250 WORDS)