Abstract: Objective To find an Objective evaluation method for the degree of thoracic collapse of stage Ⅲ tuberculous empyema, and to analyze the related factors affecting the improvement of thoracic collapse after stage Ⅲ tuberculous empyema. Method Retrospective analysis was performed on stage Ⅲ patients with tuberculous empyema who received surgical treatment in Chengdu Public Health Clinical Center from February 2018 to August 2021. Chest CT examination was performed 12 months after surgery, and the half circumference of the inner margin of the bone of the affected side and the healthy side was measured through the plane of the carina and xiphoid process, and the "thoracic collapse index" was calculated. The study population was divided into the group with significant improvement of thoracic collapse and the group without significant improvement, and the factors affecting the significant improvement of thoracic collapse were analyzed. Result A total of 62 patients were included in the study, including 46 males and 16 females, with an average age of (27.58±12.55) years. The thoracic collapse index in the carina and xiphoid plane after each follow-up period was significantly lower than that before surgery (P<0.05), and the overall trend was gradually decreasing. The thoracic collapse recovery was the best and the thoracic collapse index was the lowest 12 months after surgery. In the follow-up period of 12 months after surgery, the study population was divided into two groups: significantly improved thoracic collapse group and no significantly improved thoracic collapse group according to whether the "improvement percentage of thoracic collapse" was ≥4% or not. Multivariate logistic regression analysis showed that the disease course < 6 months (P=0.048), BMI <18.5kg/m² (P=0.043) and preoperative pleural thickness <1cm (P=0.027) were the risk factors for significant improvement of thoracic collapse after carinal plane surgery. BMI<18.5kg/m² (P=0.042) was a protective factor that significantly improved thoracic collapse after xiphoid plane surgery. Conclusion In this study, the index "thoracic collapse index" was successfully defined to quantitatively evaluate the degree of thoracic collapse in stage Ⅲ tuberculous empyema, and the related factors affecting the improvement of postoperative thoracic collapse were preliminarily found.

Key words: Tuberculous empyema, Thoracic collapse, Collapse index, Influence factor, Correlation