Introduction Current BTS guidelines recommend the utilisation of medical thoracoscopy (MT) for cytology negative, exudative pleural effusions. A large pleural cavity is required between the lung and chest wall for safe MT. The presence of little or no pleural fluid, despite there being pleural disease present, makes the procedure technically challenging with a higher potential for complications, bleeding and failure of the procedure.

Objective We compare the safety and efficiency of MT performed in patients with small or absent pleural effusions, with patients with moderate or large effusions.

Methods A retrospective review of case notes, radiology and pathology reports of patients who underwent MT between January 2010 and March 2012 was conducted. All procedures were performed or assisted by a level II thoracoscopist with the aid of live ultrasound scanning (USS). Pleural effusion size was estimated using chest x-ray and bedside USS. A small effusion was defined as blunting of the costophrenic angle only on chest x-ray and less than 100ml fluid estimation on USS. Patients were divided into two groups based on effusion size (absent or small effusion and moderate or large effusion). Data was collected and analysed for minor and major complications and diagnostic yield.

Results 43 MT were performed during the period. 88% of patients were male (n=38). The mean patient age was 70.1 years (SD 8.69). 41.9% patients had absent/small effusions (n=18). There were no major complications documented in either group. The minor complication rate was 8% in the moderate/large effusions group (n=2) and 11% in the absent/small effusions group (n=2). The minor complications noted were trapped lung, surgical emphysema, wound infection and haematoma. The diagnostic yield was 96% in the moderate/large effusions group (n=24) and 94% in the absent/small effusions group (n=17).

Conclusions Despite its technical challenges, MT can be performed safely and effectively with minimal minor complications and high diagnostic yield in patients with small pleural effusions and even when no fluid is present when performed by thoracoscopists with appropriate experience level.