THE PATHOGENSIS of atherosclerosis is as yet incompletely understood, and it may well be that ultimately, no single process will be identified as the sole cause of this disease. There are numerous contributing factors which alter athero- genesis. Some of these are heredity, race, sex, dietary habits, endocrine diseases, hypertension, and disorders in cholesterol and lipid metabolism.
The lesion in atherosclerosis is the atheroma which begins as a small, elevated, yellowish plaque in the intima. Microscopic sections reveal the lesion to consist of cholesterol and lipoid material in phagocytes which are in turn surrounded by proliferating connective tissue. Increase in connective tissue and deposition of calcium occur with the passage of time. The role played by the cholesterol in the lesion is more readily accepted by investigators at large than is the manner in which the cholesterol deposition occurs. One theory is that the cholesterol is carried into the vessel