Diagnostic value and safety of medical thoracoscopy for pleural effusion of different causes

BACKGROUND: Pleural effusions occur for various reasons, and their diagnosis remains challenging despite the availability of different diagnostic modalities. Medical thoracoscopy (MT) can be used for both diagnostic and therapeutic purposes, especially in patients with undiagnosed pleural effusion. AIM: To assess the diagnostic efficacy and safety of MT in patients with pleural effusion of different causes. METHODS: Between January 1, 2012 and April 30, 2021, patients with pleural effusion underwent MT in the Department of Respiratory Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University (Shaanxi, China). According to the discharge diagnosis, patients were divided into malignant pleural effusion (MPE), tuberculous pleural effusion (TBPE), and inflammatory pleural effusion (IPE) groups. General information, and tuberculosis- and effusion-related indices of the three groups were analyzed. The diagnostic yield, diagnostic accuracy, performance under thoracoscopy, and complications of patients were compared among the three groups. Then, the significant predictive factors for diagnosis between the MPE and TBPE groups were analyzed. RESULTS: Of the 106 patients enrolled in this 10-year study, 67 were male and 39 female, with mean age of 57.1 ± 14.184 years. Among the 74 thoracoscopy-confirmed patients, 41 (38.7%) had MPE, 21 had (19.8%) TBPE, and 32 (30.2%) were undiagnosed. Overall diagnostic yield of MT was 69.8% (MPE: 75.9%, TBPE: 48.8%, and IPE: 75.0%, with diagnostic accuracies of 100%, 87.5%, and 75.0%, respectively). Under thoracoscopy, single or multiple pleural nodules were observed in 81.1% and pleural adhesions in 34.0% with pleural effusions. The most common complication was chest pain (41.5%), followed by chest tightness (11.3%) and fever (10.4%). Multivariate logistic regression analyses showed effusion appearance [odds ratio (OR): 0.001, 95%CI: 0.000-0.204; P = 0.010] and carcinoembryonic antigen (OR: 0.243, 95%CI: 0.081-0.728; P = 0.011) as significant for differentiating MPE and TBPE, with area under the receiver operating characteristic curve of 0.977 (95%CI: 0.953-1.000; P < 0.001). CONCLUSION: MT is an effective, safe, and minimally invasive procedure with high diagnostic yield for pleural effusion of different causes.