Semi-rigid Vs Rigid Pleuroscopy for the Diagnosis for Pleural Effusion: a Multi-Centric Study

Semi-rigid pleuroscopy (SRP) has been available for nearly two decades, but studies comparing its yield with rigid pleuroscopy (RP) are scarce, monocentric and operator dependent. The primary purpose of our study was to compare the diagnostic yield and safety profile of pleural biopsies obtained by both techniques. Cross-sectional observational study including patients with undiagnosed pleural effusion submitted to pleuroscopy from September 2016 to October 2021 in two tertiary hospitals and one oncology referral hospital. RP was available in one hospital and SRP in two. Inferential statistical analysis was performed with the software SPSS v23 ® considering a statistical significance of 5%. We evaluated a sample of 223 patients and excluded 92 where pleuroscopy was performed for therapeutic purposes and biopsies were not executed. The final 131 included patients were divided into two groups: 69 (52.7%) who performed RP and 62 (47.3%) SRP. The percentage of diagnosis obtained through biopsy was slightly lower for SRP (80.6%) compared to RP (81.2%) but the difference was not statistically significant (χ2=0.006; p=0.940). The overall cumulative diagnostic yield of biopsy and cytology, was slightly higher for SRP (82.3%) compared to RP (81.2%) but, again, the difference was not statistically significant (χ2=0.026; p=0.871). Complications were described (12,9% for SRP vs 13% for RP, (χ2(1)=0.001; p=0.981), but no serious adverse events or mortality was reported. Malignancy was the most common histological diagnosis (64,1%). In our sample, the overall performance of SRP and RP, performed by independent operators at different hospitals was comparable, both in accuracy and safety.