Diagnostic yield and safety of transbronchial lung cryobiopsy using 1.7-mm probes in interstitial lung disease

Interstitial lung disease (ILD) is a heterogeneous condition that requires diagnosis and treatment through an integrated approach that combines the clinical background and radiological and histopathological findings. Transbronchial lung cryobiopsy (TBLC) has the advantage of obtaining larger tissue samples with minimal tissue damage compared to transbronchial lung biopsy, and represents a safer alternative to surgical lung biopsy. Recently, 1.7-mm single-use cryoprobes have been widely used, however, the safety and usefulness of TBLC with these probes remain unclear. The aim of this study was to evaluate the procedural details, safety, and changes in diagnostic confidence with multidisciplinary discussion (MDD) following TBLC.

We conducted a retrospective study of TBLC cases at a single university hospital in Japan. Between August 2023 to June 2024, 25 patients were enrolled in this study. Biopsies were obtained using a 1.7-mm single-use probe with a freezing duration of 5 s; the mean sample area was 16.0 mm², and the mean maximum diameter was 5.47 mm.

Complications included moderate hemorrhage in three patients (12%) and mild pneumothorax in one patient (4%). No acute exacerbations of ILD were observed. Diagnostic confidence improved after MDD in 5 out of 6 cases (83.3%) of idiopathic pulmonary fibrosis (IPF) and 7 out of 8 cases (87.5%) of hypersensitivity pneumonitis (HP).

The incorporation of TBLC pathological findings in the MDD improved diagnostic certainty and facilitated decisions regarding treatment strategies. TBLC using a 1.7-mm single-use probe with a freezing duration of 5 s can safely obtain sufficient tissue specimens for the diagnosis of ILD.