Safety and efficacy of performing medical thoracoscopy on a "dry space" using an optical trocar

Medical thoracoscopy (MT) to obtain pleural biopsies ideally requires a pleural effusion to safely access the pleural space. In the absence of an effusion ("dry space"), accessing the pleural space is more challenging, with variably reported success.

A retrospective review was performed of all MTs at a single center in New York City from January 2023 to November 2025. Documented dry spaces were selected for analysis. An optical trocar was used for direct visualization of the parietal pleura in addition to obtaining tactile feedback, to induce an ex-vacuo pneumothorax and access the pleural space. We also performed a literature review of MT performed on patients with absent or minimal pleural effusion.

A total of 226 MTs were performed, of which 54 were dry spaces. The parietal pleura was accessed and pleural biopsies were successfully performed in all cases. Some degree of adhesiolysis was required in 62 % of cases to optimize a thorough inspection of the space. Common diagnoses obtained included acute or chronic organizing pleuritis (59.3 %), followed by malignancy (24.1 %). The diagnostic sensitivity for malignancy was 100 %. There were no significant intra-procedural complications.

Dry space MT, using an optical trocar to access the pleural space, can be safely and effectively performed.