Ultrasound-guided transbronchial cryobiopsy of mediastinal and hilar lesions: A cohort study from four Swiss centres

This obervational study shares findings on the novel method of ultrasound-guided transbronchial cryobiopsy for mediastinal and hilar lesions and compares results with standard endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Patients aged 18-90 years undergoing diagnostic bronchoscopy in four Swiss centres were included. The primary goal was to compare the diagnostic yield (definitive diagnosis) between cryobiopsies and EBUS-TBNA. Tunnelling to the target lesion was performed using an electric needle knife (70.2%), a 19G-(12.8%), or a 22G-needle (17.0%). Cryobiopsies were obtained with a freezing time of 5-7 sec (17.7% with a 1.7 mm probe) or 7-10 sec (82.3% with a 1.1 mm probe). Between February 1, 2022, and November 30, 2023, 140 patients were enrolled. Cryobiopsies demonstrated a significantly higher diagnostic yield at 94.3% compared to EBUS-TBNA's 57.1% (p<0.001). For malignant cases (n=56), immunohistochemical and EGFR-results were obtainable in 88.7% of cases with cryobiopsies from a single lymph node (median of 4 probes [IQR 3 to 5]), significantly higher than the 58.5% yield obtained with EBUSTBNA (median of 3 probes [IQR 3 to 3]) from all sampled lymph nodes (p=0.004). Adverse events affected 23.6% of participants, including 10.0% with mild to moderate bleeding and 7.9% with post-procedure coughing. No deaths or mediastinum infections were observed. Cryobiopsy of mediastinal and hilar lesions not only enhances diagnostic yield compared to EBUS-TBNA but also demonstrates a favourable safety profile, suggesting its potential as a viable alternative in specific cases, potentially replacing EBUS-TBNA.