Diagnostic yield of transbronchial cryobiopsy in interstitial lung disease: a randomized trial

Transbronchial lung biopsy (TBLB) is required for evaluation in selected patients with interstitial lung disease (ILD). The diagnostic yield of histopathologic assessment is variable and is influenced by factors such as the size of samples and the presence of crush artefacts left by conventional biopsy forceps. We compared the diagnostic yield and safety of TBLB with cryoprobe sampling versus conventional forceps sampling.

This randomized clinical trial analysed data for 77 patients undergoing TBLB for evaluation of ILD; patients were assigned to either a conventional-forceps group or a cryoprobe group. Two pathologists assessed the tissue samples and agreed on histopathologic diagnoses. We also compared the duration of procedures, complications and sample-quality variables.

The most frequent diagnosis observed in the cryoprobe group was non-specific interstitial pneumonia. Histopathologic diagnoses were identified in more cases in the cryoprobe group (74.4%) than in the conventional-forceps group (34.1%) (P < 0.001), and the diagnostic yield was higher in the cryoprobe group (51.3% vs 29.1% in the conventional forceps group; P = 0.038). A larger mean area of tissue was harvested by cryoprobe (14.7 ± 11 mm(2) ) than by conventional forceps (3.3 ± 4.1 mm(2)) (P < 0.001). More grade 2 bleeding (not statistically significant) occurred in the cryoprobe group (56.4%) than in the conventional-forceps group (34.2%). No differences in other complications were observed.

TBLB by cryoprobe is safe and potentially useful in the diagnosis of ILD. Larger multisite randomized trials are required to confirm the potential benefits of this procedure. Clinical trial registration at ClinicalTrials.gov: NCT01064609.