Medical thoracoscopy/ Pleuroscopy is the procedure where the pleural cavity is explored with arigid or semi-rigid endoscope inserted through an incision in the affected intercostal space. It is included in the training programme of the chest physicians.
Indications for pleuroscopy
Diagnostic yield
A significant number of patients with pleural effusion are undiagnosed after routine cytology and closed-needle biopsy. Pleural involvement in malignancy often reveals patchy abnormalities with disease affecting more dependent parts of the pleura near the diaphragm. That is the reason why many malignant pleural effusions are underdiagnosed with the traditional diagnostic pleural procedures. Cytological examination of pleural fluid is only diagnostic in 60-80% of patients with metastatic pleural involvement and in less than 20% in patients with mesothelioma. Pleuroscopic pleural biopsy yields diagnosis in more than 90% 2.In an Iran study, 87 % of the peluroscopies were diagnostic and 67% of them were diagnosed as malignancy while the rest were diagnosed as tuberculosis1.
Procedure
It can be performed in an endoscopy suite under local anaesthesia or conscious sedation. Patient is placed in the lateral decubitus position with the affected side up. Pleural ultrasound is used to optimize the site for insertion. Under aseptic condition and local anesthesia, a small skin incision is made parallel with and centered in the intercostal space selected. Blunt dissection is performed down to the parietal pleura and then the trocar is gently inserted. Any fluid in the pleura is aspirated via a suction tube. The semi-rigid pleuroscopcis inserted through the trocar to inspect the pleural cavity and take biopsies.At the end of the procedure, the trochar is replaced with a chest drain and sutures are tied. If the pleural surfaces have appearances consistent with malignancy, pleurodesis can be performed prior to removing the port, using talc administered via an insufflator (poudrage). Chest drain is removed when the lung is re-inflated on CXR with minimal fluid or air drainage. If mesothelioma is diagnosed, thoracoscopy and chest drain tract sites need to do radiotherapy4.
Figure ( 1 ) Pleuroscopy model
Contraindications
It is contraindicated in the absence of pleural space and relatively contraindicated in patients with refractory cough, uncorrected coagulopathy and unstable hemodynamic status.
Complications
Complications include bleeding, subcutaneous emphysema, prolonged air leak, seeding of chest wall from mesothelioma, infection of the pleural space, injury to intrathoracic organs and ARDS with talc poudrage.
Pleurodesis
Pleurodesis can be either chemical or surgical. Chemicals such as bleomycin, tetracycline, povidone-iodine or talc can be used. Among them, success rate of pleurodesis with talc was better than those with other agents. A review of the English literature from 1966 to 1994 of 1,168 patients treated with chemical agents for malignant pleural effusions showed that talc was clearly the most effective, witha complete success rate of 93%3.
Current practice
As mentioned above, pleuroscopy allows us for direct visual assessment of the pleura and subsequent biopsy to get adequate samples. It also favors the removal of almost all pleural fluid in a single session. It gives us chance for pleurodesis with the sclerosant and optimal chest tube placement after assessing the extent of pleural carcinomatosis and lung expandability, all at the same sitting. When there is a condition of adhesion and loculated accumulation of pleural fluid as found in tuberculous pleural effusion, pleuroscopy allows us to do adhesiotomy to get release of the trapped lung from cob web like adhesions in addition to take pleural biopsy.
Because of these advantages, pleuroscopy has increasingly been performed by chest physicians in our current respiratory medicine practice. In the Department of Respiratory Medicine, Yangon Specialty Hospital, pleuroscopic procedures are carried out using Olympus LTF 160 flex rigid thoracoscope when the patients are presented with undiagnosed recurrent pleural effusion and suspicious malignant pleural effusion. After visualizing convincing evidence of carcinomatous involvement of pleural, pleurodesis is often performed by insufflating 4g of talc powder using a bulb syringe. The procedure is usually carried out under conscious sedation and local anesthesia in the endoscopy suite. So it is free from the risk of general anesthesia and also cost saving.
Pleuroscopy in Myanmar was pioneered by chest physicians from the Department of Respiratory Medicine, Yangon Specialty Hospital. Altogether 100 pleuroscopic procedures have been done since 2017 according to statistical data at the endoscopy centre of the department. As found in the departmental case study of pleuroscopy patients, pleuroscopy achieved the definitive diagnosis in the patients with effusion of undetermined etiologies, providing a diagnostic yield of 93.1% which was comparable to other studies ¹٫². In regards to complications related to pleuroscopy, 5.2% had minor complications: tube related infection after repeated talc slurry and transient hypotensive episode after the procedure, recovered after fluid challenge. In the subset of suspected malignant pleural effusion, the outcome of pleurodesis with talc poudrage was found to be successful in 76.5% of patients. Less pleurodesis success rate in our current practice might be explained by contribution of “lost to follow up” cases and lower dose of sclerosant usage in our patients compared with other studies³.
As a conclusion, pleuroscopy is an emerging valuable tool for chest physicians to evaluate undiagnosed pleural effusion with a high diagnostic yield. It also has satisfactory therapeutic role by successfully inducing lung expansion and pleurodesis in patients with recurrent symptomatic pleural effusion, particularly malignant pleural effusion. The complications of the procedure, on the other hand, are very rare and negligible.
Figure ( 2,3 ) Radiology of pleural effusion
Figure ( 4 ) Pleuroscopic view of tuberculous pleural effusion
Figure ( 5 )
Figure ( 6 )
Figure ( 7 )
Figure ( 8 )
Figure ( 5,6,7,8 ) Pleuroscopic view of malignant pleural effusion ane parietal pluera studded with pleural nodules
References:
- Kiani, A., Abedini, A., Karimi, M., Samadi, K., Sheikhy, K., Farzanegan, B., Abdollah, M. P., Jamaati, H., Jabardarjani, H. R. &Masjedi, M. R. (2015)Diagnostic Yield of Medical Thoracoscopy in Undiagnosed Pleural Effusion.Tanaffos. 14(4), 227-231.
- Malhotra, R., Bergh, C. C., Lee, H. J., Shepherd, R. W. &Mosenifar, Z.(ed.) (2019) Medical Thoracoscopy.
- Sahn, S. A. (2000) Talc Should Be Used for Pleurodesis, Am J RespirCrit Care Med. 162(2), 2023-2024.
- Oxford Handbook of Respiratory Medicine (2014) Medical thoracoscopy, In: Chapman, S., Robinson, G., Stradling, J., West, S. &Wrightson, J. (eds.) Thoracoscopy technique. 3rd edition. Oxford. Oxford University Press, p.816.
