REBUS-TBNA

Preoperative investigations included an enhanced CT scan of the lungs, complete blood count (CBC), liver and renal function examination, electrolytes examination, electrocardiogram (ECG), and coagulation tests. Immediately before the procedure, the operator reviewed the chest CT images and determined the lesions size and the bronchus in which was located. The patient was instructed to lie on the examination table in the supine position and received nebulized lidocaine (administered oropharyngeally) as local anesthesia. Then oxygen was provided via nasal cannula for the entire length of the procedure and monitored for vital signs. In our current cohort intravenous sedation or general anesthesia was not applied.

The procedure was performed with the Olympus BF-P260F bronchoscope (Olympus Co. Ltd., Tokyo, Japan). After a systematic inspection of the tracheobronchial tree (Figure 1A), the REBUS (UM-S20-20R, Olympus Co. Ltd., Tokyo, Japan) 20-MHz probe was inserted into the target bronchus on the bases of the CT-scan images as discussed above. Once the best possible ultrasound image of the peribronchial lesion was obtained with the REBUS probe (Figure 1B), the segmental bronchus was recorded, and the optimal puncture location was selected. Before the withdrawal of the ultrasound probe, the probe depth was marked. Subsequently, a 19-gauge WANG TBNA needle (MWF-319, ConMed Company, New York, USA) was inserted through the biopsy channel at the same length of the mark done on the REBUS probe, and a needle biopsy was performed at the location that was selected under ultrasound image (Figure 1C). Then, a 60-mL syringe was attached to the end of the needle with negative pressure aspiration applied. The process was repeated to obtain 5 to 6 samples. Brush cytology was performed routinely to avoid missing any mucosal involvement by the lesion not macroscopically identified on the airway exam. Biopsy tissues would be sent for histopathological examination and smear cytological examination. If an accurate diagnosis could be obtained from the biopsy sample, the sample would be considered as a diagnostic sample and the patient would be defined as patient with positive diagnosis.

The representative images during REBUS-TBNA procedure. (A) Bronchoscopic image of the right middle lobe bronchus of a patient; (B) radial ultrasound image of a lesion in the right middle lobe; (C) puncture of the right middle lobe lesion. REBUS, radial endobronchial ultrasound; TBNA, transbronchial needle aspiration.

The specimens were fixed in a 10% formalin solution for histopathological examination. The molecular testing was polymerase chain reaction (PCR)-based assay. DNA or RNA would be extracted from biopsy samples according to the protocol. Reverse transcription would be done to convert RNA into cDNA for further PCR. The aberrations of EGFR/ALK/ROS1/KRAS/BRAF were detected by Multi-Gene Mutations Detection Kit (Amoy, Xiamen, China) according to manufacturer’s protocol.

After the procedure, if bleeding occurred, local hemostasis was carried out using diluted epinephrine and cold saline. After confirmation of no active bleeding, the procedure was completed. Intraoperative and postoperative adverse events were recorded including bleeding, chest pain, hypoxia, and postoperative infection. All procedures were performed by the same bronchoscopist, who was aided by the same nurse, to avoid the potential bias.