Abstract Rationale Conventional transbronchial cryobiopsy (CB) for peripheral pulmonary lesions (PPLs) requires scope removal and reinsertion. A novel technique enabling CB while maintaining the bronchoscopic wedge in the target bronchus is desirable. We developed a novel method for direct retrieval of CB specimens using a 1.1-mm cryoprobe through the working channel of a therapeutic bronchoscope (TB). This study evaluated its safety and diagnostic utility. Methods This prospective study was conducted at NHO Nagoya and Okayama Medical Centers in Japan (March 2023-March 2025). Patients with PPLs suspected of lung cancer underwent forceps biopsy (FB) with 1.9-mm forceps, followed by CB (1.1-mm cryoprobe) via the TB (3.0-mm working channel). Endobronchial ultrasonography with a guide sheath (EBUS-GS) was performed to confirm the target bronchus. FB specimens were retrieved using GS. For CB, the cryoprobe was inserted through the GS into the lesion, and both cryoprobe and GS were retrieved in an en bloc through the channel. After each CB, the bronchoscope was wedged for 3 min and bleeding severity was graded. The primary endpoint was bleeding grade. Secondary endpoints included other complications, diagnostic yield, specimen size, success rate of the procedure, and biomarker tests. Results Of the 100 enrolled patients, 96 were analyzed. The median lesion size was 41.1 mm (range 12-88). Using TB, lesions were successfully identified and biopsied in 88 cases; in eight cases, EBUS could not localize the lesion. Among 88 patients, FB was performed in all 88 patients and CB in 84. The median number of specimens was five for the FB (range, 5) and three for the CB (range, 0-4). The median freezing time was 6 s (range, 2-8 s). Two retrieval failures occurred because they became stuck at the tip of the bronchoscope. Severe bleeding occurred in two cases requiring balloon occlusion. Bleeding grades were Grade 0, 43.2%; Grade 1, 45.5%; Grade 2, 9.0%; Grade 3, 2.3%. Other complications included pneumonia and two pneumothoraxes. Specific diagnostic yields were 76.0% for FB and 79.1% for CB; overall yield was 87.5%, with CB providing the sole diagnosis in 10 cases. CB specimens were significantly larger than FB specimens (7.06 vs. 2.46 mm², p 0.001). Among the 32 cases that underwent multiplex genomic testing, CB specimens were used in 75%, FB in 12.5%, and both in 12.5%. Conclusions Direct retrieval of CB specimens via a TB working channel is safe, feasible and provides diagnostically and molecularly useful tissue. This abstract is funded by: None
Takigawa et al. (Fri,) studied this question.