tube may be removed once there is no further air leak.

As mentioned above, procedure modifcations have been implemented to decrease hospital stay. A tunneled pleural catheter may be placed at the time of the thoracoscopy either in addition to the surgical chest tube or alternatively in lieu of the chest tube. If a tunneled pleural catheter is placed in lieu of a chest tube, then the drainage line and chest tube adapter are attached to the one-way valve and the tube connected to the pleurovac. For diagnostic procedures, that is, without any manipulation of the visceral pleura and no air leak at the end of the case, the chest tube may be removed or the tunneled catheter capped once the lung has fully re-in ated.

As the patient receives minimal sedation, they are generally sent to the recovery room to emerge from any sedation and to have a chest X ray performed to verify the chest tube position and determine whether the lung has fully re-in ated. If diagnostic, it may not be necessary for the patient to be admitted to the hospital for further monitoring unless complications arise. On the other hand, suction may be necessary for at least 24 hours if attempting pleurodesis.

Most North American pulmonologists do not perform visceral pleural or parenchymal biopsies via medical thoracoscopy. When performed by pulmonologists, they are mostly done using dedicated cautery to seal the air leak simultaneously. Thoracoscopic rigid cautery probes exist to assist with cauterization of localized bleeding to achieve hemostasis. They are also useful for interruption of the sympathetic chain. Additional thoracoscopic procedures not routinely performed in North America will not be addressed in this chapter.

Medical Thoracoscopy Versus VATS

Medical Thoracoscopy and VATS (Video-­ Assisted Thoracoscopic Surgery) differ technically although there exists overlap in their indications particularly in the setting of malignant and infectious effusions as well as pneumothorax management [33]. Both allow for a

comprehensive pleural evaluation. Medical thoracoscopy may be performed in a procedure space such as an endoscopy suite in some hospitals whereas VATS is performed in a surgical suite under general anesthesia and single lung ventilation. In medical thoracoscopy either a pneumothorax is induced in advance of the procedure or as a part of the procedure allowing the lung to passively de ate. Patients undergoing medical thoracoscopy breathe spontaneously throughout the procedure while a dual lumen endotracheal tube is usually placed for VATS to isolate the lungs and achieve collapse of the surgical side.

Although there is overlap between these two procedures, VATS has a wide array of additional applications including lung resection. As such it also has a higher overall complication rate that may be attributable at least in part to the need for general anesthesia and intubation as well as the technical aspects of the additional procedures performed. Both procedures can readily be employed for diagnosis and staging cancer in malignant effusions. The advantage of medical thoracoscopy in this setting is that it can be performed without the need/risk of general anesthesia in stage IV cancer patients. Also, with newer technical modifcations, patients may be discharged several days sooner even in the case of interventions such as pleurodesis.

There have been many technical advances in VATS, particularly with the development of articulating instruments and stapling devices to mitigate post procedure air leak. This procedure not only allows for pleural intervention but also other lung and esophageal procedures. The most appropriate procedure for the patient should be selected and this decision should take into account patient factors such as comorbid illness, patient preference if there is procedural equipoise, and cost.

Conclusion

Medical thoracoscopy is both safe and effective in the management of pleural disease. It has both diagnostic and therapeutic indications including diagnosis of unclear exudates, management of

malignant pleural disease, and infectious effusions. It is minimally invasive and may be performed in a procedural area under moderate sedation allowing for a potentially broader spectrum of patients than VATS including less clinically robust patients. It may be considered an alternative to VATS for procedural indications that overlap. The role of medical thoracoscopy is expanding and future research in the potential use of the pleura for drug delivery and stimulation of the immune system are exciting. Finally procedural innovations are allowing for very early discharge and lower costs of care in these patients.

References

1.\Loddenkemper R, Mathur P, Lee P, Noppen M. History and clinical use of thoracoscopy/pleuroscopy in respiratory medicine. Breathe. 2001;8:145–55.

2.\Pastis N, Nietert P, Silvestri G. Variation in training for interventional pulmonary procedures among US pulmonary/critical care fellowships. Chest. 2005;127:1614–21.

3.\Light R, MacGregor M, Luchsinger P, Nall W. Pleural effusions: the diagnostic separation of transudates and exudates. Ann Intern Med. 1972;77:507–13.

4.\Ferreiro L, Gude F, Toubes M, Lama A, Suárez-­ Antelo J, San-José E, González-Barcala F, Golpe A, Álvarez-Dobaño J, Rábade C, Rodríguez-Núñez N, Díaz-Louzao C, Valdés L. Predictive models of malignant transudative pleural effusions. J Thorac Dis. 2017;9:106–16.

5.\Michaud G. Approach to unclear exudates. Principles and practice of interventional pulmonology. New York: Springer Science and Business Media; 2013.

6.\Ozcakar B, Martinez C, Morice R, Eapen G, Ost D, Sarkiss M, Chiu H, Jimenez C. Does pleural uid appearance really matter? The relationship betweenuid appearance and cytology, cell counts, and chemical laboratory measurements in pleural effusions of patients with cancer. J Cardiothorac Surg. 2010;5:63.

7.\Hooper C, Lee YC, Maskell N. Investigation of a unilateral pleural effusion in adults: British Thoracic Society pleural disease guideline 2010. Thorax. 2010;65 Suppl 2:ii4–17.

8.\Yarmus L, Feller-Kopman D, Imad M, Kim S, Lee HJ. Procedureal volume and structure of interventional pulmonary fellowships: a survery of fellows and fellowship program directors. Chest. 2013;144:935–9.

9.\Wei Y, Shen K, Lv T, Liu H, Wang Z, Wu J, Zhang H, Colella S, Wu F, Milano M, Zhan P, Song Y, Lu Z. Comparison between closed pleural biopsy and

medical thoracoscopy for the diagnosis of undiagnosed exudative pleural effusions: a systematic review and meta-analysis. Transl Lung Cancer Res. 2020;9:446–58.

10.\Wan Y, Zhai C, Lin X, Yao Z, Liu Q, Zhu L, Li D, Li X, Wang N, Lin D. Safety and complications of medical thoracoscopy in the management of pleural diseases. BMC Pulm Med. 2019;19:125.

11.\Sanchez-Armengol A, Rodriguez-Panadero F. Survival and talc pleurodesis in metastatic pleural carcinoma, revisited. Report of 125 cases. Chest. 1993;104:1482–5.

12.\Xie L, Wang X, You W, Ma X, Wang Y, Liu T, Jian S. Predictors of survival in non-small cell lung cancer patients with pleural effusion undergoing thoracoscopy. Thoracic Cancer. 2019;10:1412–8.

13.\Sun H, Vaynblat A, Pass H. Diagnosis and prognosis-­ review of biomarkers for mesothelioma. Ann Transl Med. 2017;5:244.

14.\Kindler H, Ismaila N, Armato A, Bueno R, Hesdorffer M, Jahan T, Jones C, Miettinen M, Pass H, Rimmer A, Rusch V, Sterman D, Thomas A, Hassan R. Treatment of malignant pleural mesothelioma: American Society of Clinical Oncology clinical practice guideline. J Clin Oncol. 2018;36:1343–73.

15.\Chen YP, Huang HY, Lin KP, Medeiros LJ, Chen TY, Chang KC. Malignant pleural effusions correlate with poorer prognosis in patients with diffuse large B-cell lymphoma. Am J Clin Pathol. 2015;143:707–15.

16.\Schwarz C, Lubbert H, Rahn W, Schonfeld N, Serke M, Loddenkemper R. Medical thoracoscopy: hormone receptor content in pleural metastases due to breast cancer. Eur Respir J. 2004;24:728–30.

17.\Bays AM, Pierson DJ. Tuberculous pleural effusion. Respir Care. 2012;57(10):1682–4.

18.\Kong X, Zeng H, Chen Y, Liu T, Shi Z, Zheng D, Zhou R, Cai S, Chen P, Luo H. The visual diagnosis of tuberculous pleuritis under medical thoracoscopy: a retrospective series of 91 cases. Eur Rev Med Pharmacol Sci. 2014;18:1487–95.

19.\Kirsch C, Kroe D, Azzi R, Jensen W, Kagawa F, Wehner J. The optimal number of pleural biopsy specimens for a diagnosis of tuberculous pleurisy. Chest. 1997;112:702–6.

20.\Dipper A, Jones H, Bhatnagar R, Preston N, Maskell N, Clive A. Interventions for the management of malignant pleural effusions: a network meta-analysis. Cochrane Database Syst Rev. 2020;4(4):CD010529.

21.\Wahidi M, Reddy C, Yarmus L, Feller-Kopman D, Musani A, Shepard RW, Lee H, Bechara R, Lamb C, Shofer S, Mahmood K, Michaud G, Puchalski J, Rafeq S, Cattaneo S, Mullon J, Leh S, Mayse M, Thomas S, Peterson B, Light R. Randomized trial of pleural uid drainage frequency in patients with malignant pleural effusions. The ASAP trial. Am J Respir Crit Care Med. 2017;195:1050–7.

22.\Reddy C, Ernst A, Lamb C, Feller-Kopman D. Rapid pleurodesis for malignant pleural effusions: a pilot study. Chest. 2011;139:1419–23.

23.\Tschopp JM, Bintcliffe O, Astoul P, Canalis E, Driesen P, Janssen J, Krasnik M, Maskell N, Van Schil P, Tonia T, Waller D, Marquette CH, Cardillo G. ERS task force statement: diagnosis and treatment of primary spontaneous pneumothorax. Eur Respir J. 2015;46:321–35.

24.\Hallifax R, Yousef A, Jones H, Corcoran J, Psallidas I, Rahman N. Effectiveness of chemical pleurodesis in spontaneous pneumothorax recurrence prevention: a systematic review. Thorax. 2017;72:1121–31.

25.\Ferrer J, Montes J, Villarino M, Light R, Garcia-­ Valero J. In uence of particle size on extrapleural talc dissemination after talc slurry pleurodesis. Chest. 2002;122:1018–27.

26.\Plojoux J, Foudrarakis M, Janssens JP, Soccal P, Tschopp JM. New insights and improved strategies for the management of primary spontaneous pneumothorax. Clin Respir J. 2019;13:195–201.

27.\Ravaglia C, Gurioli C, Tomassetti S, Casoni G, Romagnoli M, Guriolo C, Agnoletti V, Poletti V. Is medical thoracoscopy effcient in the management of multiloculated and organized thoracic empyema? Respiration. 2012;84:219–24.

28.\Rahman N, Maskell N, West A, Teoh R, Arnold A, Mackinlay C, Peckham D, Davies AN, Kinnear W, Bentley A, Kahan B, Wrightson J, Davies H, Hooper

C, Lee YCG, Hedley E, Crosthwaite N, Choo L, Helm E, Gleeson F, Nunn A, Davies R. Intrapleural use of tissue plasminogen activator and DNase in pleural infection. N Engl J Med. 2011;365:518–26.

29.\Luengo-Fernandez R, Penz E, Dobson M, Psallidas I, Nunn A, Maskell N, Rahman N. Cost-effectiveness of intrapleural use of tissue plasminogen activator and DNase in pleural infection: evidence from the MIST2 randomized controlled trial. Eur Respir J. 2019;54:1801550.

30.\Kheir F, Thakore S, Mehta H, Jantz M, Parikh M, Chee A, Kaphle U, Sisnega C, Fernandez-Bussy S, Majid A. Intrapleural fbrinolytic therapy versus early medical Thoracoscopy for treatment of pleural infection: randomized controlled clinical trial. Ann Am Thorac Soc. 2020;17:958–64.

31.\Rozman A, Camlek L, Marc-Malovrh M, Triller N, Kern I. Rigid versus semi-rigid thoracoscopy for the diagnosis of pleural disease: a randomized pilot study. Respiration. 2013;18:704–10.

32.\Michaud G, Berkowitz D, Ernst A. Pleuroscopy for diagnosis and therapy for pleural effusions. Chest. 2010;138:1242–6.

33.\Shojaee S, Lee H. Thoracoscopy: medical versus sur- gical-­in the management of pleural disease. J Thorac Dis. 2015;7:S339–51.

Introduction and Defnition of the Procedure

Pulmonary emphysema is a chronic, debilitating, often fatal disease, characterized by progressive destruction of the lung parenchyma, hyperin a- tion, reduced lung elasticity, and impaired gas exchange. Patients with severe emphysema complain of progressive dyspnea as the hyperin ated lung becomes entrapped in a rigid chest wall. Medical treatment of emphysema offers limited symptomatic relief, but has failed thus far to improve survival. Lung volume reduction surgery, a therapeutic option in advanced emphysema, while successful in a selected group of patients, is associated with considerable morbidity and mortality [1]. The landmark National Emphysema Treatment Trial (NETT) found a striking improvement in survival in patients undergoing surgery with upper lobe predominant emphysema and poor exercise tolerance [1]. Despite such promising fndings, the NETT may be credited with a widespread reluctance to refer patients for the procedure because of the reported 5% mortality, which was alarmingly high in some high-risk patients [2]. Furthermore, 50% of the patients in the surgical arm suffered from pro-

L. M. Seijo Maceiras (*)

Pulmonary Department, University Clinic, Navarra, Pamplona, Spain

e-mail: lseijo@unav.es

longed hospitalizations, air leaks, and/or infection. Consequently, only 538 procedures were reported in the US in an 8.5 year time period between 2003 and 2011 [3]. Since then, expert centers have continued to perform a steadily increasing number of procedures in a highly selected minority of patients with severe emphysema [4]. Reported 6-month operative mortality has been low in this setting with limited median lengths of intensive care unit (ICU) and hospital stay and sustained improvement at 5 years [5].

Pulmonologists have been investigating a variety of minimally invasive alternatives to lung volume reduction surgery for years. The promise of a technique or device capable of reproducing the benefts of the surgical procedure without incurring the side effects, mortality, and morbidity of surgical lung volume reduction is appealing for obvious reasons. Not surprisingly, interest in endoscopic lung volume reduction (ELVR) continues to expand to this day. In general, ELVR can be defned as a minimally invasive bronchoscopic procedure devoted to the reduction in total or regional lung volumes in patients with severe emphysema and signifcant exertional dyspnea [6]. Some procedures rely on device insertion, including endobronchial valves, coils, and bypass stents, while others instill bioactive substances such as a polymer, water vapor, or even autologous blood, with identical therapeutic intentions. The methods are diverse, but rely for the most part on the exible bronchoscope using deep