Safety and Efficacy of Direct Cryobiopsy Specimen Retrieval Through the 3.0-mm Working Channel of a Therapeutic Bronchoscope Using a 1.1-mm Cryoprobe: A Multicentre Prospective Observational Study.

BACKGROUND AND OBJECTIVE: Cryobiopsy using a 1.1-mm cryoprobe through a therapeutic bronchoscope with a 3.0-mm working channel permits en bloc retrieval of the cryoprobe and guide sheath while the bronchoscope remains wedged in the target bronchus, potentially facilitating immediate haemostatic control. This study investigated the safety and efficacy of this technique. METHODS: This prospective observational study enrolled patients with peripheral pulmonary lesions suspected of lung cancer who underwent forceps biopsy (FB), followed by cryobiopsy using a 1.1-mm cryoprobe through a therapeutic bronchoscope with a 3.0-mm working channel. The primary endpoint was procedural safety, as assessed by bleeding grade. The secondary endpoints included procedure-related complications, diagnostic yield, specimen size, procedural success rate, and biomarker analysis success rate. RESULTS: Of 100 enrolled patients, 96 were included in the analysis, and 84 underwent cryobiopsy. Bleeding severity was Grade 0 in 35.4% (34 of 96), Grade 1 in 41.7% (40 of 96), Grade 2 in 8.3% (8 of 96), and Grade 3 in 2.1% (2 of 96) of patients. Diagnostic yields were 77.0% (74 of 96) for FB and 79.1% (76 of 96) for cryobiopsy, with an overall yield of 87.5% (84 of 96). Cryobiopsy provided the sole diagnosis in 10 patients and yielded significantly larger specimens than FB (7.06 vs. 2.46 mm2; p < 0.001). The success rate of multiplex genetic testing was 95.8% for cryobiopsy (23 of 24). CONCLUSION: Direct retrieval of cryobiopsy specimens through the working channel of a therapeutic bronchoscope is safe and feasible, yielding larger specimens with complementary diagnostic value.