For massive pleural effusion, drain the pleural effusion slowly by use of an indwelling catheter or by repeated thoracentesis, starting from the day before the procedure to prevent re-expansion pulmonary edema.

On the day of the procedure, the patient is placed in the lateral decubitus position, with the diseased side facing upward. The puncture site should be confirmed by checking for pleural effusion and pleural adhesion using chest ultrasound. After administration of local anesthesia with 1 % lidocaine, a 1–2 cm incision is made, followed by blunt dissection through the muscle layers of the chest wall until the parietal pleura is exposed. During this procedure, ensure that adequate anesthesia is delivered to the subcutaneous and muscle layers. Upon reaching the parietal pleura, gently strip it off using a Kocher clamp to avoid injury to the closely apposed visceral pleura. After dissection of the parietal pleura and confirmation of collapse of the affected lung, a disposable flexible trocar (8 mm inner diameter) is inserted carefully before proceeding with inspection using the flex-rigid pleuroscope.

Upon confirming the location of the pleural lesion, local anesthesia with 1 % lidocaine is administered by subpleural injection needle (4–6 mm, 23–25 G) to reduce a pleural pain before taking biopsies (10–20 times) using alligator forceps (Fig. 25.3). After hemostasis is confirmed on the biopsy site, remove the thoracoscope and flexible trocar and place a double-lumen chest tube (20–24 Fr), which will be connected to a water-seal bottle for continuous thoracic drainage after the procedure. If there is a large amount of residual pleural effusion, there is no need for immediate application of negative pressure after thoracoscopy closure to avoid re-expansion pulmonary edema.

The main purpose of medical thoracoscopy is to obtain a definitive diagnosis of pleural diseases by visual inspection and biopsy (Figs. 25.3, 25.4, 25.5, 25.6, 25.7, 25.8 and 25.9). The most frequent diseases are cancerous pleurisy from lung cancer, malignant pleural mesothelioma, tuberculous pleurisy, and nonspecific inflammation. Other etiologies are pleural metastasis from other cancer types, malignant lymphoma, empyema, concomitant pneumonia, concomitant pancreatitis, Meigs’ syndrome, and collagen diseases. Pleural lesions on thoracoscopy tend to be similar and nonspecific; therefore, these are difficult to clearly classify without biopsy.

It is important to take note that since the local anesthesia under thoracoscopy limits procedure time, quick determination of the pleural biopsy site is required. In the next section, we introduce our system of reporting the thoracoscopic findings that we use in our hospital.

Since most pleural lesions consist of polypoid lesions and pleural thickening, it is advisable to take findings of these lesions separately. Systematic taking of abnormal intrathoracic findings will shorten procedure time and can reduce errors.

Malignant pleural mesothelioma is difficult to diagnose by small specimens. The IT knife 2 (Olympus) was specifically designed to electrosurgically treat early gastric carcinoma. It consists of a conventional diathermic needle knife with a ceramic ball at the tip; the outer diameter is 2.2 mm and the length is 4 mm. The IT knife 2 is a disposable tool with a preferred working channel diameter of at least 2.8 mm.

We use the IT knife 2 for thick pleural lesions that are difficult to grasp by flexible forceps (Figs. 25.10 and 25.11) [17]. Local anesthesia is administered almost similar to the method described in Sect. 25, but an additional pleural bulge should be made. Following this, a pinhole is made through the bulge using coagulation forceps. The tip of the IT knife 2 is inserted into the hole, followed by a circular incision through the full thickness of the affected pleura using ENDO-CUT mode electric current at 30–50 W. The incised pleura is then carefully removed by flexible forceps.

Cancerous pleurisy from primary lung cancer is often seen as scattered nodules. Fusion of the pleural lesions may be seen in some cases of malignant pleural mesothelioma (Fig. 25.8), tuberculous pleurisy (Fig. 25.4), or malignant lymphoma (Fig. 25.7). In malignant diseases, pleural thickening may be frequently seen not only in malignant pleural mesothelioma but also in various cases of metastatic cancerous pleurisy. Especially, cancerous pleurisy due to metastatic breast cancer exhibits a high degree of pleural thickening. In our series, full-thickness pleural biopsy specimen collected by IT knife 2 was useful for determining the diagnosis and for immunohistochemistry analysis [17]. To differentiate from primary lung cancer, breast cancer may sometimes metastasize to the pleura in the form of cavitations on the pleural surface (Fig. 25.6).