Affixment arrangements of peribronchiolar alveoli in normal and emphysematous lungs.

Our investigation of the radially affixed alveoli of nonrespiratory bronchioles showed that the interalveolar interval was basically constant for normal bronchioles of all sizes, with a mean value of 0.146 mm. The mean interalveolar interval increased significantly to 0.173 and 0.209 mm, respectively, in the two most severe grades of emphysema. The pattern of alveolar affixment to the walls of bronchioles was also altered in emphysema, with irregular interruptions, variations in size and shape of abutting luminal spaces, and loss of alveolar attachment surface. These changes reflected the disruptive phase of emphysema and corroborated previous studies. A dominant extrinsic force normally responsible for bronchiolar patency is thus compromised. Any bronchiole so affected would logically be prone to collapse or contracture of its wall, luminal deformities, diminution of luminal caliber, and retarded airflow.