Diagnostic Yield and Safety of Medical Thoracoscopic Biopsy in Undiagnosed Exudative Pleural Effusion: A Five-Year Retrospective Study From a Tertiary Care Center in South India

BACKGROUND: Medical thoracoscopy is a minimally invasive procedure with high diagnostic yield in undiagnosed exudative pleural effusions. There is limited data on its efficacy and safety from high-volume tertiary centers in India, considering the changing etiological spectrum. METHODS: This is a retrospective observational study including all consecutive patients who underwent medical thoracoscopy for undiagnosed exudative pleural effusion at a tertiary care teaching hospital in South India over a five-year period. Data were obtained from departmental records and analyzed for diagnostic yield, etiology, macroscopic findings, therapeutic interventions, complications, and outcomes. RESULTS: A total of 305 patients were included (mean age 57 ± 15.5 years; 60.3% male). An etiological diagnosis was achieved in 303 patients, yielding a diagnostic yield of 99.4%. Malignancy was the most common diagnosis (64.6%), predominantly lung adenocarcinoma (77.1% of malignancies), followed by benign causes (35.4%), with tuberculosis accounting for 14.4% overall. Nodules (59.7%) and adhesions (41.3%) were the most frequent macroscopic findings, correlating strongly with malignant and infective etiologies, respectively. Talc pleurodesis and adhesiolysis were performed in 18.7% and 23.0% of cases, respectively. Complications were predominantly minor: post-procedure pain (66.6%), followed by subcutaneous emphysema (7.2%). Major complications were rare (hemorrhage 0.3%, prolonged air leak