Abstract: Abstract：Objective To observe the pathological change of visceral pleura in patients with chronic obstructive pulmonary disease (COPD), and to discuss the relationship between the changes and COPD airflow limitation. Methods A total of 70 patients received the pulmonary lobectomy or partial resection because of lung tumor in Tianjin Chest Hospital from May 2014 to August 2015 were selected in this study. According to the results of pulmonary function test, the patients were divided into COPD group [forced expiratory volume in one second (FEV1)/ forced vital capacity (FVC) <70%， n=40] and control group (FEV1/FVC≥70%， n=30). The lung tissues, which was not the lesion areas, were used to make tissue sections. The Elastica Van Gieson (EVG) method was used to stain the sections. The thickness of visceral pleural and the proportion of elastic fibers in visceral pleural were observed and calculated under a microscope in the two groups. Results The specimens were derived from upper and middle lobes in 22 cases of COPD group, and from lower lobe in 18 cases. Specimens were derived from upper and middle lobes in 17 cases of control group, and from lower lobe in 13 cases. There were no statistical differences in sampling sites between two groups (χ2=0.019， P＞0.05). The visceral pleural thickness and the proportion of elastic fibers in visceral pleural were significantly thinner in COPD group than those of control group (P < 0.01). In both COPD group and control group, visceral pleural thickness was significantly thinner in upper and middle lobes than that of lower lobe (P < 0.05), but the proportion of elastic fibers in visceral pleural of upper, middle lobes showed no statistical difference compared with that of the lower lobe (P＞0.05). Conclusion The thinner visceral pleural and the reduction of elastic fibers in visceral pleural are one of the causes of expiratory airflow limitation in COPD patients.

Key words: Chronic Obstructive Pulmonary Disease, visceral pleura, elastic fiber, pulmonary elastic retraction force, expiratory airflow limitation