Thrombo-Embolic Primary Pulmonary Arteriosclerosis

That diverse factors are concerned in causing arterial pathological changes largely confined to lungs is clear from a review published by McKeown (1952). Only one of these factors, incorpora- tion of fibrin into arterial intima, is here considered as a cause of pulmonary arteriosclerosis and cor pulmonale. Goedel (1930), Belt (1939), and according to Duguid (1946) Rokitansky were all aware that incorporation of blood clot into vascular intima produced lesions simulating arteriosclerosis. Duguid once more directed attention to this fact and following his lead, various workers undertook experiments to test his conclusions which were based on human autopsy material By injecting fibrin emboli intravenously into rabbits it has been shown that lesions like arteriosclerosis may be induced in small branches of the pulmonary artery (Harrison, 1948 and 1951; Muirhead and Montgomery, 1951; and Barnard, 1953). These workers used emboli prepared in vitro either from the animal's own blood or from blood of a different animal.