Prospective Evaluation of Safety and Diagnostic Efficacy of Medical Thoracoscopy in Undiagnosed Exudative Pleural Effusion: Experience From a Tuberculosis High-Burden Country.

Introduction: Pleural effusion is due to the pathological accumulation of pleural fluid in the pleural space, 25%-30% of which may remain undiagnosed despite the combination of biochemical, microbiological, and pathological tests and closed pleural biopsy. Medical thoracoscopy may help physicians diagnose such cases. We aimed to study the diagnostic yield of medical thoracoscopy in patients with undiagnosed exudative pleural effusion and assess the safety profile of the medical thoracoscopy.

Methodology: A cross-sectional descriptive study was conducted on 105 patients with undiagnosed pleural effusion. Medical thoracoscopy was performed using an Olympus semi-rigid thoracoscope (LTF 160 Evis Pleurovideoscope, Japan) as per standard protocol. Multiple pleural biopsies were taken and sent for histopathology examination, NAAT (nucleic acid amplification test), and MGIT (mycobacteria growth indicator tube). Post-procedure, the patients were evaluated for any complications.

Results: A total of 105 patients were enrolled in the study. The mean ± SD age was 55.1 ± 13.6 years. Sixty-three (60%) patients were males. The diagnostic utility of medical thoracoscopy was found in 94 (89.5%) patients. The diagnosis of tuberculosis (TB) was made in 34 (32.3%) patients, and 48 (45.7%) patients were diagnosed with malignant pleural effusion. Adenocarcinoma of the lung was the most common malignancy diagnosed (32 patients, 66.6%). Five (5.31%) patients had dual etiology of pleural effusion: tubercular and malignancy. The most common complication was chest pain following the procedure (99.4%). One patient developed pneumomediastinum and was managed conservatively. There were no major adverse events after the procedure.

Conclusions: Medical thoracoscopy has a high diagnostic yield and favorable safety profile with minimal complications. Excessive reliance on the level of ADA (adenosine deaminase) may further delay the diagnosis. Dual etiologies like TB coexisting with malignancy should be considered in TB high-burden countries.