Dual-function Semirigid Thoracoscopy Versus Rigid Thoracoscopy for the Diagnosis of Pleural Disease

Diagnostic yield is defined as the percentage of participants for whom the allocated thoracoscopic pleural biopsy provides a specific histopathological diagnosis. Malignant pleural disease and other defined histopathological diagnoses will be classified as diagnostic results. Non-specific pleuritis, fibrinous pleuritis, non-interpretable specimens, and cases in which no biopsy is obtained will be classified as non-diagnostic results.

Procedural sedative and analgesic requirements will be assessed by recording the total dose of each sedative or analgesic agent administered during thoracoscopy, including midazolam, pentazocine, and tramadol. The dose of each agent will be recorded separately in milligrams and summarised by treatment group

Disease-specific diagnostic sensitivity is defined as the percentage of participants with a specific final diagnosis according to the reference standard whose allocated thoracoscopic pleural biopsy provides a specific histopathological diagnosis supporting the same disease. Participants with non-specific biopsy findings who are subsequently diagnosed with malignant pleural disease or tuberculous pleuritis during follow-up will be classified as false-negative biopsy results for the corresponding disease.

Sampling quality will be assessed using specimen size, specimen depth, and specimen interpretability. Specimen size will be measured as the largest cross-sectional area of the processed biopsy specimens on microscopic glass slides using ImageJ software and reported in square millimetres. Specimen depth will be assessed according to the presence of thoracic wall fatty tissue. Specimen interpretability will be classified as easily interpretable, interpretable with some difficulty, interpretable with great difficulty, or non-interpretable.

Procedure duration will be measured in minutes from skin incision to completion of chest tube placement and wound closure.

Operator-assessed device performance will include image quality, ease of manoeuvring, ease of obtaining a biopsy sample, and the operator's expectation that the biopsy sample will provide a definitive histological diagnosis. Each domain will be assessed immediately after the procedure using a visual analogue scale ranging from 0 to 100, with higher scores indicating better operator-assessed performance.

Patient-reported post-thoracoscopy pain will be assessed using a 100-mm visual analogue scale while at rest and while coughing. Scores range from 0 to 100, with higher scores indicating more severe pain.

Procedure-related complications will be classified as major or minor complications. Major complications include empyema, major haemorrhage defined as a drop in haemoglobin of at least 1 g/dL or requiring blood transfusion, persistent air leak for more than 3 days, and re-expansion pulmonary oedema. Minor complications include subcutaneous emphysema, operative site infection, non-infective fever, and minor haemorrhage.

Postprocedural length of hospital stay is defined as the number of days from the date of thoracoscopy to hospital discharge.

Direct medical costs during the index hospitalization will be extracted from hospital billing records. These costs include procedure-related costs, anaesthetic and analgesic medication costs, chest tube and drainage-related costs, postprocedural imaging and management costs, and postprocedural hospitalization costs. Costs will be reported in Chinese Yuan.