Radial EBUS guided mini cryobiopsy without blocker balloon can safely diagnose non-malignant and malignant peripheral pulmonary lesions
K. Bennett*a (Dr), M. Salamonsena (Dr)
a Fiona Stanley Hospital, Perth, AUSTRALIA
Background: Transbronchial lung cryobiopsy overcomes many limitations of forceps biopsy, including increased sample size and reduced crush artefact. Application of cryobiopsy to diagnose peripheral pulmonary lesions (PPLs) has been limited due to difficulty guiding the cryoprobe to the correct location and concerns over bleeding. We hypothesise that using radial-EBUS to exclude at-risk vessels followed by 1.1mm mini cryobiopsy without blocker balloon will be safe and effective to diagnose PPLs.
Method: Participants underwent bronchoscopy with a single proceduralist between July 2020 and February 2022. All had radial-EBUS localisation of PPLs via guidesheath. Following FNAx2, radial-EBUS was used to select a biopsy location without adjacent blood vessels. Under fluoroscopic guidance, a single cryobiopsy (1.1mm probe, freeze time 12sec) was taken and the bronchoscope removed en bloc for retrieval. BAL was subsequently collected. No patients had a blocker balloon.
Results: 39 procedures were included, 56% in males with a median age of 69. Average lesion size was 31mm and location according to CT third was predominantly middle(30%), outer(24%), or both(19%).
Overall diagnostic yield of cryobiopsy was 49%(19/39) but for non-malignant conditions was 67%(4/6). A further 5 malignant cases were diagnosed from BAL/FNA (total yield 62%). Of the cases where no diagnosis was obtained, 2/15 cases still have no confirmed diagnosis and 2/15 were later diagnosed benign. 11/15 were later diagnosed malignant, in one of these cases the cryobiopsy freeze time had been reduced to 6 seconds due to a nearby vessel on EBUS.
One pneumothorax (11mm) and one episode of mild but persistent bleeding requiring bronchoscope wedging and tranexamic acid occurred.
Conclusion: Radial-EBUS guided mini cryobiopsy through guidesheath without blocker balloon is safe and effective for diagnosing PPLs. It has a particular advantage for the diagnosis of non-malignant conditions. More research is required to determine optimal technique.
Disclosure of funding source(s): none