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[Chronic obstructive pulmonary disease and pulmonary structural remodeling].

OBJECTIVE
To understand the pathological characteristics of the lungs in 20 autopsy cases of chronic obstructive pulmonary disease(COPD) complicated with cor pulmonale and its relationship with structural remodeling of the lungs.


METHODS
The lungs of 20 autopsy cases of COPD complicated with cor pulmonale were fixed in 10% formalin or by low pressure 18.4-33.4 mm Hg perfusion with 10% formalin. The lungs were cut sagitally into large slices with 2 cm in thickness, and the percentage of the emphysematous areas was calculated by point counting. The pathological characteristics of bronchioles and the stromal fibrosis area were examined microscopically and quantitatively using a latticed micrometer (Zeiss). The distribution and the ratio of type I to type III collagen in the lung tissue were determined using a sirius red-polarizing microscopy-morphmetry method.


RESULTS
Of the 20 cases of COPD, irregular and saccular emphysema were the most frequent (17/20). 10 cases had moderate and high degree of emphysema, and 6 cases showed hypertrophy of the right ventricle (heart weight > 400 g). The mean area of stromal fibrosis auounted for total area of the examined lungs was (27.1 +/- 2.9)% and control group (12.0 +/- 1.8)%. The ratio of the area of the type I collagen to type III collagen was 5.6:1 (control group 1.3:1). All 1504 bronchioles showed chronic inflammation, 38% of which revealed acute exacerbation, and 53% of which showed lumen stenosis and fibrotic obstruction.


CONCLUSIONS
Acute and chronic bronchiolitis and peri-bronchiolitis are the essential pathological changes in COPD, and also are the key link of the structural remodeling of the pulmonary tissue and vessels.