Pleuroscopy for the Diagnosis of Cancer in Patients with Pleural Effusion: A Review of the Diagnostic Accuracy, Safety, Cost-Effectiveness and Guidelines [Internet]

Excerpt

A pleural effusion is characterized by an excessive accumulation of fluid in the pleural space and the underlying cause may be benign or life threatening. The appropriate treatment of pleural effusions can be determined once the etiology is known, however, the etiology is unclear in approximately 20% of cases. A pleural aspiration revealed a positive cytology diagnosis of malignancy in 60% of cases and a positive result of mesothelioma in 32% of cases. The subsequent step in evaluating pleural effusions of unknown cause has been closed pleural biopsies which have been noted as affordable and accessible in clinical settings, however, this procedure has been less sensitive compared to image-guided pleural biopsy or medical thoracoscopy (MT) in the diagnosis of malignant pleural effusion. The conventional closed pleural biopsy is conducted with either Abrams or Cope biopsy needles however this technique does not offer direct visualization of the pleura.^, The field of diagnostic procedures have evolved to overcome the poor sensitivity associated with closed pleural biopsy in the diagnosis of pleural effusions with unknown etiology.

Pleuroscopy, also referred to as MT or local anesthetic thoracoscopy (LAT), is a minimally invasive diagnostic procedure that entails the direct visualization of the pleura followed by a biopsy of visually abnormal areas.^, Medical thoracoscopy is performed by a non-surgeon in a non-operation room (e.g., endoscopy unit) under local anesthesia and moderate sedation.^, Key steps undertaken during pleuroscopy include preparation and positioning of the patient, aspiration of fluids, induction of pneumothorax, local anesthesia and sedation (if applicable), introduction of the trocar, assessment of the thoracic cavity via pleuroscope using photography or video, retrieving multiple biopsy samples followed by controlling bleeding. The reported sensitivity of pleuroscopy ranges from 90 to 100%.

Medical thoracoscopy may be delivered via rigid or semi-rigid (flexi-rigid) instruments. The rigid instrument has been identified as the most commonly used for MT however, semi-rigid is being increasingly used. Overall, the diagnostic results and tolerability of rigid and semi-rigid thoracoscopy are comparable. Major complications reported with MT include prolonged air-leak, hemorrhage, empyema, and port site tumour growth. Minor complications due to MT may encompass subcutaneous emphysema, wound infection, fever, hypotension and cardiac arrhythmias.

In contrast to MT, video-assisted thoracoscopic surgery is more invasive and conducted by a surgeon in an operating room under general anesthesia with single lung ventilation and involves multiple ports.

While the literature suggests pleuroscopy to be safer and less invasive compared to VATS, there is variation in the use of pleurosocpy and VATS as some centres are using one technique in favor of the other.

The purpose of this review is to evaluate the diagnostic accuracy of pleuroscopy in patients with pleural effusions of unknown etiology; their adverse effects, their cost-effectiveness and evidence-based guidelines if any.