Biochemists implicate serum cholesterol and physiologists describe vascular stress factors, but the embryologist has had little to say about the pathogenesis of atherosclerosis. Dalith1 suggests that an embryological approach to atherosclerosis may explain focal deposits of calcium and atheromatous plaques in the wall of the thoracic aorta. This investigator identified the sites of preference of calcium deposition and studied the nature of these findings. Examination of 100 aortic-arch specimens from all age groups revealed a depression, or dimpling, of the intimal surface of the aorta with thinning of the wall. These structural changes are present at the levels of insertion of the ligamentum arteriosum (or patent ductus arteriosus) and the origin of the left subclavian artery corresponding to the aortic connections of the sixth and probably the fifth embryonic aortic arches.
Dalith found that selective calcification of the aortic knob in elderly subjects is often due to deposition of