Diagnostic sensitivity and safety of visceral pleural biopsy under semi-rigid medical thoracoscopy in patients with undiagnosed exudative pleural effusions: a retrospective study.

BACKGROUND

Medical thoracoscopy (MT) is primarily employed to obtain histopathological evidence via parietal pleural biopsy. However, parietal pleural lesions are not uniformly accessible, and evidence on visceral pleural biopsy remains limited.

OBJECTIVES

This study aimed to investigate the diagnostic sensitivity and safety of visceral pleural biopsy performed under semi-rigid MT in patients with undiagnosed exudative pleural effusions (EPEs).

DESIGN

Single-center retrospective observational study.

METHODS

A retrospective analysis was conducted on 459 patients with undiagnosed EPEs who underwent pleural biopsy via MT. Among the 324 patients who met the inclusion and exclusion criteria, 38 who underwent visceral pleural biopsy and 74 who underwent parietal pleural biopsy were included in the final analysis after propensity score matching. The diagnostic sensitivity and safety were determined for both groups.

RESULTS

The diagnostic sensitivity was 78.9% in the visceral pleural group (85.7% for malignancy and 55.6% for tuberculosis) and 91.9% in the parietal pleural group (92.6% for malignancy and 89.5% for tuberculosis). Subgroup analysis based on macroscopic patterns suggested that the difference in diagnostic sensitivity was mainly driven by cases of tuberculous pleural effusion presenting as diffuse pleural thickening under MT, whereas comparable sensitivities were observed between the two groups in malignant pleural effusion and nodular-type tuberculous pleural effusion. The median time to chest tube removal was 2 days in both the visceral pleural group and the parietal pleural group. No statistically significant differences were observed between groups.

CONCLUSION

Medical thoracoscopic visceral pleural biopsy is safe and demonstrates comparable diagnostic sensitivity to parietal pleural biopsy for malignancies and tuberculosis presenting as nodular lesions under MT in patients with undiagnosed EPEs.