Utility of semirigid thoracoscopy in the diagnosis of pleural effusions: A systematic review

Background and Objective: Pleural effusion of undetermined etiology (PEUE), where blind pleural aspirate/biopsy fails to yield an answer, often needs histologic study for a definitive diagnosis. Several studies have shown the potential utility of medical thoracoscopy (MT) in PEUE; results, however, are not uniform and a majority are available for rigid thoracoscopy. We sought to determine the diagnostic accuracy of the relatively new technique of semirigid thoracoscopy in PEUE through this systematic review. Methods: The electronic search was carried out in PubMed without language restriction. References of relevant records and abstracts were hand searched. Articles were selected based on the following criteria: (1) prospective study, (2) based on original research, (3) enrolled consecutive patients with PEUE, (4) full paper available in English, (5) MT carried out under local anesthesia (LA) using semirigid (flex-rigid) instrument, and (6) reported sufficient data to construct a 2 ∞ 2 contingency table. We assessed the study quality and extracted data independently and in duplicate using a standardized data extraction form. Results: Five studies met the inclusion criteria, encompassing 154 patients. Pooled sensitivity (95% CI) was 0.97 (0.92-0.99), specificity (95% CI) was 1.00 (0.69-1.00), positive likelihood ratio (95% CI) was 5.47 (1.11-16.86) and negative likelihood ratio (95%CI) was 0.08 (0.04-0.18). No major complications or mortality was noted. Conclusion: Semirigid thoracoscopy seems to be a safe, simple, and accurate tool for undiagnosed pleural effusions. It is well tolerated and is devoid of major complications. Further studies with sound methodology will further help to define the future role of this procedure.