Diagnostic performance and safety of image-guided pleural biopsy and medical thoracoscopy for undiagnosed exudative pleural effusion: a systematic review and network meta-analysis.

INTRODUCTION

Undiagnosed exudative pleural effusions often require pleural biopsy for a definitive diagnosis. The optimal sampling method, particularly when medical thoracoscopy is compared with image-guided pleural biopsy, remains uncertain.

METHODS

This systematic review and network meta-analysis included studies that reported on the diagnostic performance and safety of medical thoracoscopy and image-guided pleural biopsy approaches. The primary outcome of this study was diagnostic yield, and the secondary outcomes included other diagnostic parameters (e.g. sensitivity, negative likelihood ratio, and negative predictive value), post-procedure complications, and biopsy quality and number. A frequentist network meta-analysis was performed to compare and rank the diagnostic performance and safety of various pleural biopsy methods using a random-effects model. A subgroup analysis was performed according to the presence of pleural nodules or thickness and the type of biopsy needles used.

RESULTS

An analysis of 64 studies involving 8744 patients revealed that rigid medical thoracoscopy had the highest diagnostic yield (95.0%), followed by cryobiopsy (93.1%), semirigid medical thoracoscopy (92.3%), and ultrasound elastography (UE)-guided biopsy (92.3%). Closed pleural biopsy had the lowest yield (75.1%). The current evidence is insufficient to establish the superiority of any biopsy method in terms of complications. The network meta-analysis ranked rigid medical thoracoscopy as having the highest overall diagnostic yield, closely followed by UE-guided biopsy, with no statistically significant differences between image-guided biopsy and rigid medical thoracoscopy.

CONCLUSION

Closed pleural biopsy consistently has a low diagnostic yield and is not recommended as a first-line biopsy method for patients with undiagnosed exudative pleural effusions. Rigid medical thoracoscopy offers distinct clinical value for a complete visual inspection, large biopsies, and potential pleurodesis, particularly in suspected mesothelioma cases. The currently available evidence does not support the routine replacement of semirigid medical thoracoscopy with cryobiopsy. Computed tomography-guided biopsy may be preferred in cases involving thickening ≥10 mm or small target lesions. Conversely, ultrasound-guided biopsy may be appropriate for lesions measuring ≥3 mm with a clear acoustic window. UE-guided pleural biopsy shows promise as an emerging option, although the evidence is limited. In tuberculous pleurisy, medical thoracoscopy may offer higher diagnostic sensitivity in certain settings, particularly in high-prevalence areas. The current evidence is insufficient to establish a clear advantage for any biopsy method regarding the overall complication risk.