Assessment of a Randomized Controlled Trial on the Safety of Pre-placing Bronchial Balloons in Transbronchial Lung Cryobiopsy for Diagnosing Interstitial Lung Disease

Abstract Rationale and objectives: Bleeding is a major complication of transbronchial lung cryobiopsy (TBLC), and pre-placing a bronchial balloon is one of the clinical practices used to prevent it, but with very weak evidence, which should be confirmed. This study aimed to conduct whether pre-placing a bronchial balloon in TBLC for diagnosing interstitial lung disease (ILD) is more safety. Materials and methods: In this prospective, single-center, randomized controlled trial, patients with suspected ILD were enrolled and randomly assigned to pre-placed-balloon and none-pre-placed-balloon groups. The primary outcome was incidence of moderate bleeding in each group. The secondary endpoints were the incidence of severe bleeding, pneumothorax and other procedural complications. Results: Exactly 250 patients were enrolled between August 2019 and March 2022, with 125 in each group. There were no significant differences in severe bleeding between the none-pre-placed-balloon group and pre-placed-balloon group (1.6% vs. 0.8%; adjusted p=0.520), while more moderate bleeding occurred in the none-pre-placed-balloon group (26.4% vs. 6.4%, adjusted p=0.001), as well as more use of hemostatic drug (28.0% vs. 6.4%, adjusted p=0.001). Three patients in the none-pre-placed-balloon group used the bronchial balloon. More samples could be acquired in the pre-placed-balloon group than in the none-pre-placed balloon group (3.8±0.9 vs 3.1±0.9, p＜0.001). There were no significant differences in multidisciplinary discussion (MDD)between the two groups (89.6% vs 91.2%, adjusted p=0.182). Conclusion: A pre-placed bronchial balloon can reduce the incidence of moderate bleeding and increase the confidence of the bronchoscopists. However, it had no effect on increasing the diagnostic rate of MDD and reducing severe bleeding. Registration number:NCT04047667 (www.clinicaltrials.gov identifier)