Endobronchial ultrasound-guided transbronchial cryobiopsy through a working channel potentially improving safety and efficacy

Endobronchial ultrasound (EBUS)-guided transbronchial cryobiopsy (TBCB) is a novel method for the biopsy of hilar and mediastinal lesions. Conventional cryobiopsy requires simultaneous removal of the cryoprobe and EBUS scope from the airway, resulting in delayed observation of the biopsy site and application of hemostasis, which may lead to an increased risk of complications, especially bleeding. Moreover, during repeated passes of the cryoprobe, re-identification of the lesion is time-consuming. We developed a novel method for direct collection through a working channel during EBUS-TBCB. We performed the procedure under local anesthesia without intubation. After EBUS-transbronchial needle aspiration, the cryoprobe was introduced into the target lesion through the puncture tract for real-time EBUS visualization. A freezing time of up to 4 s allowed the cryobiopsy specimens to pass through the working channel. Retaining the EBUS scope within the airway allowed immediate observation of the biopsy site, and to immediately suction and apply hemostasis using an EBUS balloon, which led to safer cryobiopsy even without intubation. The next cryopass could then be performed. In our two representative cases, we made a definite diagnosis with three and four cryobiopsy specimens, with procedure lengths of 2.2 and 3.0 min, respectively. Only mild bleeding was observed in both cases.