Pulmonary Alveolar Lesions Following Open Heart Surgery

Lungs of patients in cases of mitral insufficiency were studied to observe the influences of cardiopulmonary bypass. In addition to preoperative pathological conditions of lungs, more marked changes were noted in the type II alveolar epithelial cells and the interstitium postoperatively.Dilatation of capillaries and interstitial edema became evident. Concomitantly, a decreased number of granules containing lamellar structures, enlargement and fusion of these granules, and invasions of swollen and coarse lamellar structures to a granule forming a bulky conglomeration were notable. Other changes demonstrated in the cytoplasmic matrix were an increase of electron density and a dilatations of granular endoplasmic reticulum. No definite conclusion was drawn from the present investigations alone, however, structural alterations described in the paper are suggestive of resulting changes of lung surfactant, which will be a cause of pulmonary syndrome because of poor ability to keep the alveoli open.