Comparison between closed pleural biopsy and medical thoracoscopy for the diagnosis of undiagnosed exudative pleural effusions: a systematic review and meta-analysis.

Background: Exudative pleural effusion (EPE) is a common diagnostic challenge. The utility of medical thoracoscopy (MT) and closed pleural biopsy (CPB) to aid in the diagnosis of EPE has been reported in many published studies. Herein, we perform a systematic review and meta-analysis to compare the diagnostic yield and safety of CPB and MT in EPE. Methods: Four databases were searched for studies reporting the diagnostic yield of CPB and MT for EPE. The quality of the included studies was evaluated according to the quality assessment of diagnostic accuracy studies (QUADAS) tool. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and complication risks were compared between the two groups. Results: Ten studies dealing with CPB and twenty-three studies dealing with MT for the diagnosis of EPE were included in this meta-analysis. Pooled sensitivity, specificity, PLR, NLR and DOR of CPB group was 77%, 99%, 32.55, 0.22, 165.71, respectively, while pooled sensitivity, specificity, PLR, NLR and DOR of MT group was 93%, 100%, 10.82, 0.08, 162.81, respectively. The area under the summary receiver operating characteristic (SROC) curve of CPB and MT were both 0.97. The ability of CPB to diagnose nonmalignant diseases was like MT (69% vs. 68%), while the ability was lower than that of MT to diagnose malignant diseases (72% vs. 92%). The pooled diagnostic accuracy of CPB and MT for mesothelioma was 26% (95% CI, 14-38%) and 42% (95% CI, 22-62%) (P<0.001), respectively. The rate of complications with CBP was lower than that reported for MT. Conclusions: CBP is a relatively accurate tool with a lower complication rate compared to MT in the diagnosis of EPE, especially in diagnosing non-malignant diseases. We confirm the utility of MT in the diagnostic workup of malignancy (especially mesothelioma); however, in selected cases, CPB could be used as the first diagnostic approach with a favorable safety profile.