Transbronchial lung cryobiopsy (TBLC) has been increasingly utilised to diagnose diffuse parenchymal lung diseases (DPLDs) and lung cancers; however, TBLC protocols have not yet been standardised and the rate of complications associated with this procedure vary widely. Therefore, this prospective multicentre observational study investigated the safety and utility of the TBLC technique in patients with diffuse and localised respiratory diseases.This study was conducted at multiple medical centres in Japan between July 2018 and April 2019. The study's primary end-point was the rate of severe or serious adverse events associated with TBLC. Adverse events included bronchial bleeding, pneumothorax, pneumonia, respiratory failure, and an acute exacerbation of interstitial pneumonia. Adverse events were graded according to severity. During the TBLC procedure, an endobronchial balloon catheter for bronchial blockade was used in all patients. Pathological confidence and quality of specimens were categorised into three groups.A total of 112 patients were included. Neither severe nor serious adverse events were identified; therefore, the primary end-point was met. Nineteen patients (17%) experienced no bronchial bleeding. Mild or moderate bronchial bleeding was identified in 67% and 16% of patients, respectively. Mild pneumothoraces were identified in four patients (3.6%). The safety profile in patients aged ≥75 years was not significantly different from younger patients. Definite or probable pathological diagnoses were made in 84.9% of patients.This TBLC protocol with routine use of an endobronchial balloon had an acceptable safety profile and diagnostic yield in patients, including elderly ones, with diffuse and localised respiratory diseases.
