Background: Transbronchial lung cryobiopsy (TBLC) has an increasing value in diagnosing interstitial lung disease (ILD). The use of a small cryoprobe (1.9-mm) rather than a larger cryoprobe (2.4-mm) is suggested with no differences in diagnostic yields of ILD, and with lower risk of bleeding and pneumothorax. The 1.1-mm probe was only recently developed to be used in TBLC. Whether the diagnostic yield and safetyof TBLC with 1.1-mm probe needs to be confirmed.
Methods: A prospective, single-center, randomized controlled trial was conducted. Patients with suspected ILD were enrolled and randomly assigned to the 1.1-mm probe group and 1.9-mm probe group. The primary outcome was the diagnostic yield which was determined by MDD after TBLC. The secondary outcome measures included sample quality, bleeding, pneumothorax, cost-effectiveness, and other procedural complications.
Results: 224 patients were enrolled from November 2020 to February 2023, with 112 patients in each group. The average surfaces of samples were 20.2±7.9 cm2 and 16.3±14.3 cm2 (p=0.019) in 1.9-mm probe group and 1.1-mm probe group, respectively. While there were no significant differences in diagnostic yield (80.4% vs 79.8%, p=0.782) and sample quality (5.7±0.7 vs 5.7±0.7; p=0.862) between the two groups. There were also no differences between moderate bleeding (14.7% vs 11.3%, p=0.617). More pneumothorax occurred in the 1.1-mm probe group (7.1% vs 1.8%, respectively) but there was no statistical significance between the two groups.
Conclusions: Compared with 1.9-mm probe, TBLC with 1.1-mm probe also has a good performance in the diagnosis of ILD. While the 1.1-mm probe still needs to be improved and it needs to be paid attention to during the TBLC procedure to prevent the occurrence of pneumothorax.