Fig. 19.1
Preparation of the guide sheath. (a) Cut the proximal end of the GS by 3 cm and (b) insert the metallic sheath from there until its distal tip is confirmed to coincide with that of the GS (c); this way, the TBNA apparatus can be pushed out without damaging the GS (d). GS, guide sheath; TBNA, transbronchial needle aspiration (Adopted from Takai et al. [1])
Observe the endobronchial route as usual and visualize the lesion using radial EBUS (R-EBUS) through a GS.
Position the GS in the lesion, as appropriate, and remove the R-EBUS probe. Then, insert the TBNA apparatus with the covering metallic sheath into the GS.
An assistant pushes the needle toward the lesion under simultaneous X-ray fluoroscopy guidance.
After jabbing the target lesion, the assistant creates a negative pressure through the 20-ml syringe and moves the TBNA apparatus back and forth. Note that instead of the operator, the assistant is the one who performs the needle aspiration, while the operator secures the position of the scope and GS (Fig. 19.2).
Fig. 19.2
Operation of the needle apparatus and syringe by assistants, as detailed in Sect. 19.3.5
After about ten times of needle aspiration, close the stopcock while maintaining the negative pressure; otherwise, you might end up pushing the specimen back.
Retract the TBNA apparatus into the metallic sheath and remove it from the GS.
After puncture, push out the contents of the needle onto a glass slide for cytology. If you find a core specimen, transfer it to a container with formalin and send it for tissue diagnosis. For culture purposes, transfer the samples into a container with normal saline.
While the assistants process the specimen, the operator reconfirms the position of the lesion using R-EBUS. It is assumed that GS-TBNA would create a tract through the barrier to the lesion and enable easier localization and biopsy (Fig. 19.3) [2]. The goal of this procedure is to improve not only the additional yield of TBNA but also the overall diagnostic accuracy, including that of forceps biopsy and other tools. Ideally, it is desirable to confirm by TBNA first then alternate with R-EBUS scanning until the probe shifts from a position of “adjacent to” the lesion to “within” the lesion.
