Y. Fana (Dr), ZS. Huanga (Dr), K. Kontogiannib (Dr), XL. Wua (Dr), K. Sunc (Dr), WL. Fua (Dr), WM. Kueblerd (Prof), FJ. Herth*b (Prof)

a Xinqiao Hospital, Third Military Medical University, Chongqing, China, Chongqing, CHINA ; b Thoraxklinik, and Translational Lung Research Center Heidelberg, University of Heidelberg, Heidelberg, Germany, Heidelberg, GERMANY ; c Three Gorges Central Hospital, Chongqing University, Chongqing, China, Chongqing, CHINA ; d Charit√© Universit√§tsmedizin, Berlin, Germany, Berlin, GERMANY

* felix.herth@med.uni-heidelberg.de

Background: Transbronchial mediastinal cryobiopsy is a novel sampling technique for mediastinal disease. Despite of few lung cancer misdiagnoses, its improved diagnostic yield for non-lung cancer lesions compared to endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), suggests it as a potential complementary technique to conventional biopsy. This randomised study determined the safety profile and added value of the combined use of transbronchial mediastinal cryobiopsy and the standard EBUS-TBNA.

Methods: Patients with at least one mediastinal lesion of 1 cm or more in the short axis that needs diagnostic bronchoscopy were enrolled from hospital sites in Europe and China. Participants were randomly assigned to the combined use of EBUS-TBNA and transbronchial mediastinal cryobiopsy (combined group) or EBUS-TBNA alone (control group) in a 1:1 ratio. Co-primary endpoints were procedure-related complications and diagnostic yield. This study is registered with ClinicalTrials.gov, number NCT04572984.

Results: Between Oct, 2020 and Sep, 2021, 271 patients were recruited and randomly assigned: 136 to the combined group and 135 to the control group. The addition of cryobiopsy to standard sampling significantly increased the overall diagnostic yield for mediastinal lesions, as shown by either “between-group” (92.6% versus 80.7%, P=0.004) or “within-patient” (94.0% versus 82.1%, P=0.003) analyses. Diagnostic yields were similar for mediastinal metastasis (98.6% versus 98.6%, P=1.00), while the combined approach was more sensitive than standard needle aspiration in benign disorders (93.8% versus 66.7%, P=0.001). Furthermore, the combined approach resulted in an improved suitability for molecular and immunological tests of non-small cell lung cancer. The incidence of adverse events related to biopsy procedure did not differ between the combined and control group, and no severe complications leading to death or disability were reported.

Conclusion: The addition of mediastinal cryobiopsy to EBUS-TBNA resulted in a significant improvement of the diagnostic yield for mediastinal diseases, with a reassuring safety profile.

Disclosure of funding source(s): none