Diagnostic utility of medical thoracoscopy in undiagnosed exudative pleural effusions

Abstract

Background: Medical thoracoscopy is a minimally invasive technique to inspect the pleural space and to perform biopsy of pleural lesions under direct vision. In this study, the diagnostic utility of thoracoscopy for undiagnosed exudative lymphocytic pleural effusions from a tertiary care respiratory center will be discussed. Materials and Methods: In a retrospective analysis of thoracoscopic procedures, we performed between September 2017 and August 2019, the yield of thoracoscopic pleural biopsy for achieving a diagnosis in undiagnosed exudative lymphocytic pleural effusions was evaluated. Undiagnosed exudative pleural effusions were defined as pleural effusions where an etiologic diagnosis could not be ascertained by initial pleural fluid biochemical and microbiological analysis, including protein, sugar, lactate dehydrogenase, Gram and acid-fast bacilli stains and Mycobacterium tuberculosis culture, pleural fluid adenosine deaminase levels, and at least two pleural fluid cytologies negative for malignant cells or other definite causes. We analyzed the clinical, radiological, cytological, and histopathological data of the patients and also the complications of thoracoscopy. Results: We performed thoracoscopy in 68 cases of undiagnosed exudative pleural effusions using the rigid thoracoscope. The overall diagnostic yield of thoracoscopic pleural biopsy was 95.6% in patients with undiagnosed exudative pleural effusions. Malignant pleural effusion was diagnosed in 67.6% of patients, while tuberculosis was diagnosed with pleural biopsy in 25% of patients. Three cases of subcutaneous emphysema, 2 cases of postprocedure fever were observed, and one patient had prolonged air leak. Conclusion: Medical thoracoscopy has a good diagnostic yield in patients with undiagnosed exudative lymphocytic pleural effusions and is a safe procedure as well.