EBUS-TBNA can be performed on an outpatient basis under conscious sedation. The bronchoscope is usually inserted orally, since the ultrasound probe on the tip will limit nasal insertion. Some investigators prefer the use of the endotracheal tube or rigid bronchoscopy under general anesthesia. An endotracheal tube larger or equal to size 8 is required due to the size of the EBUS-TBNA scope. Cough reflex is minimal under general anesthesia which may be an advantage during the procedure. However, operators should be careful not to put excessive pressure with the probe on to the airway. The disadvantage of the endotracheal tube is that it causes the bronchoscope to lie in the central position within the airway which creates difficulty to bring its tip in close proximity to the trachea or bronchus. The use of the laryngeal mask airway has been shown to be useful during EBUS-TBNA.

Two separate monitors should be used during EBUS-TBNA: one for the endoscopic image and one for the ultrasound image (Fig. 18.4). Since the linear curved array transducer is on the tip of the flexible bronchoscope, the optic located proximal to the ultrasound probe is set at a 35-degree forward oblique angle. Therefore, in order to obtain a straight view, the tip of the bronchoscope needs to be slightly flexed down. The bronchoscopist also needs to be aware that the 7.5-MHz ultrasound probe attached on the tip of the bronchoscope is not visible without the inflation of the balloon. Careful attention should be made to advance the scope atraumatically.

After achieving local anesthesia and conscious sedation, the CP-EBUS is inserted orally and passed through the vocal cords by visualizing the anterior angle of the glottis (Fig. 18.5a). Once the bronchoscope is introduced into the airway until the desired position is reached for EBUS imaging (Fig. 18.5b), the balloon is inflated with normal saline to achieve a maximum contact with the tissue of interest. The tip of the CP-EBUS is flexed and gently pressed onto the airway. Ultrasonically visible vascular landmarks are used to identify the specific lymph node stations according to the International Lymph Node Map by the International Association for the Study of Lung Cancer. The Doppler mode is used to confirm and identify surrounding vessels as well as the blood flow within lymph nodes. There is a standard EBUS classification system of sonographic features of lymph nodes on EBUS. One can predict malignant versus benign during lymph node staging with EBUS-TBNA. Lymph nodes larger than 1 cm in short axis, round shaped, distinct margins, heterogeneous echogenicity, with the presence of coagulation necrosis sign and without the presence of central hilar structures are suspicious for malignancy and need to be biopsied (Fig. 18.6).

After identifying the lesion of interest, the bronchoscopic image of the airway is simultaneously visualized to localize the insertion point of the needle. Once the point of entry is decided using small landmarks on the airway, the dedicated TBNA needle is fastened on to the working channel of the bronchoscope. The manipulation of the needle is a very important element of performing EBUS-TBNA and is shown in Fig. 18.7. The sheath adjuster knob is loosened, and the length of the sheath is adjusted so that the sheath can be visualized on endoscopic image (Fig. 18.5c). The tip of the bronchoscope is flexed up for contact, and the lymph node is visualized again on ultrasound image. After the needle adjuster knob is loosened, the needle can be passed through the airway into the lymph node. The cartilaginous ring should be avoided during penetration (Fig. 18.5d). Once the needle is confirmed inside of the lymph node, the internal stylet is used to clear out the internal lumen, which may become clogged with bronchial membrane. The internal sheath is then removed, and negative pressure is applied with the Vaclok syringe. In case of a hyper vascular lymph node, negative pressure may cause bloody samples; thus, EBUS-TBNA can be done without suction. The needle is moved back and forth inside the lymph node to obtain samples. Finally, the needle is retrieved inside of the outer sheath, and entire needle is removed from the bronchoscope.

It is extremely important to process the specimen obtained by EBUS-TBNA in a proper way to achieve maximum results. Although the EBUS-TBNA procedure can be performed successfully by following the steps explained in this chapter, handling of the specimen may differ between centers, and this would depend on the preference of the cytopathologist and thus should follow your institutional standards. The internal stylet is usually used to push out samples. With the presence of a cytopathologist, the first few drops are placed on the slide glass, and smears are made for rapid on-site cytological evaluation using Diff-Quik staining (Fig. 18.8). The rest of the specimen is placed in a 50-ml conical filled with normal saline for cellblock preparation. The remaining specimen within the needle is also washed in this conical.

The bronchoscope is advanced into the right lower lobe bronchus. The tip of the CP-EBUS is flexed up against the lower lobe bronchus just proximal to where the basal bronchus branches. Station #12R can be visualized adjacent to the interlobar pulmonary artery.

Straighten and withdraw the bronchoscope to the intermediate bronchus. Turn to the 2-o’clock position and flex the tip just distal to the entrance of the right upper lobe bronchus. Station #11R can be visualized with the interlobar pulmonary artery running distal to the lymph node.

Withdraw the bronchoscope to the right main bronchus. Turn the tip to the 3-o’clock position and flex the tip to visualize station #10R. Lymph nodes identified distal to the azygos vein is station #10R.

Station #7 can be visualized from either the right or the left main bronchus. On the right side, turn to the 12-o’clock position and flex the tip against the right main bronchus to visualize the right main pulmonary artery. After confirmation with the Doppler mode, turn the tip counterclockwise to the 9-o’clock position to visualize station #7.