Mini Thoracoscopy vs Semirigid Thoracoscopy in Exudative Pleural Effusions

Undiagnosed pleural effusion is a diagnostic dilemma especially in exudative pleural effusions (EPE). 20-40 % are unable to be attributed to a specific diagnosis, even after thoracentesis and closed pleural biopsy. Thoracoscopy has been demonstrated to increase the diagnostic yield in undiagnosed EPE. The diagnostic yield of thoracoscopy in malignant and TB pleural effusion ranges from 91% to 94% and 93% to 100%, respectively. Rigid thoracoscopy has traditionally been the modality of choice. The recently introduced semirigid thoracoscope provides ease of handling like a flexible bronchoscope. However, there are concerns about the diagnostic yield of semi-rigid thoracoscopy when compared with rigid thoracoscopy. According to the available literature, the yield of semirigid and rigid thoracoscopy is almost similar if adequate pleural biopsy is obtained. However there are concerns that with semi-rigid thoracoscope, there might be greater incidence of inability to obtain adequate pleural biopsy. On the other hand, the use of conventional rigid thoracoscope may be associated with greater procedure related pain.Mini-Thoracoscopy is a newer rigid thoracoscopy instrument which is smaller in diameter (5.5 mm) and may allow pleural biopsy with a smaller incision. There is scant literature on its utility. The investigators hereby propose to undertake a randomized comparison of rigid 'mini thoracoscope' vs semi rigid thoracoscope in undiagnosed pleural effusions.