SCANNING ELECTRON-MICROSCOPIC MORPHOMETRY OF EMPHYSEMA IN HUMANS

We quantitated the holes in alveolar waits in 11 nonemphysematous lung s and in 11 lungs with mild emphysema, all of which were removed at su rgery. We found that in the nonemphysematous lungs, 94.1% of the holes were smaller than 10 mu m in diameter and only 0.2% were larger than 20 pm. In the lung parenchyma distant from emphysema, both the maximum diameter of the holes and the diameter of alveoli increased. In the p arenchyma between emphysema, the areas of alveolar walls represented b y holes also increased, as did the average hole area and number of hol es per alveolus. We found that alveolar holes in the regions between e mphysema correlated better with pulmonary function tests than did thos e in regions distant from emphysema. The maxim um diameter of holes an d the number of holes per alveolus correlated with functional residual capacity, residual volume, closing capacity expressed as a proportion of total lung capacity (CC/TLC), and static recoil pressure of the lu ng at TLC. Emphysema correlated with CC/TLC and with the transpulmonar y pressure at 90% TLC. Bronchiolar lesions were not related to pulmona ry function tests. Our data provide support for the hypothesis that th e tissue surrounding emphysematous lesions contributes to loss of reco il.