Rigid versus semi-rigid thoracoscopy for the diagnosis of pleural disease: a randomized pilot study

Background and objective: Thoracoscopy with a semi-rigid instrument is a recent technique successfully used for diagnosing pleural diseases. However, there are concerns about the diagnostic adequacy of biopsy samples obtained by semi-rigid procedures when compared with rigid thoracoscopy. The purpose of this study was to compare the size, quality and diagnostic adequacy of biopsy specimens obtained at semi-rigid and rigid thoracoscopy in a prospective, randomized fashion.

Methods: Patients with pleural effusion of unknown origin and/or pleural irregularities suspicious for pleural malignancy were included after less invasive means of diagnosis had failed. All procedures were performed under local anaesthesia with intravenous sedation/analgesia with a single point of entry. Patients were randomly assigned to a rigid instrument procedure (Olympus EndoEYE WA50120A, forceps) or semi-rigid instrument procedure (Olympus LTF-160, FB-55CR-1 forceps).

Results: Eighty-four patients were randomized. Five of them were excluded because of lack of pleural space. Thirty-eight patients were assigned to a rigid and 41 to a semi-rigid procedure, with mean follow up 24.1 (±8.1) months after the procedure. The average size of the sample obtained by rigid thoracoscopy was 24.7 mm(2) (±12.9), and 11.7 mm(2) (±7.6) by semi-rigid thoracoscopy. There were no differences in the quality and interpretability of the specimens assessed by the pathologist. The diagnostic accuracy was 100% for the rigid procedure and 97.6% for the semi-rigid procedure.

Conclusions: The samples obtained by semi-rigid thoracoscopy were smaller, but of adequate quality. The diagnostic accuracy was comparable with that of rigid thoracoscopy in the evaluation of pleural disease.