Late Breaking Abstract - Comparison of ultrathin bronchoscope versus thin bronchoscope for the diagnosis of peripheral pulmonary lesions without fluoroscopy: a randomized trial

<bold>Background:</bold> Ultrathin bronchoscope (UTB) with a 3.0-mm outer diameter shows a better biopsy performance than thin bronchoscope (TB) for the diagnosis of peripheral pulmonary lesions (PPLs) with the guidance of fluoroscopy. However, the diagnostic performance and safety of UTB versus TB without fluoroscopy have not been studied yet for the diagnosis of PPLs. <bold>Methods:</bold> This was a prospective, randomized, non-inferior, multicenter study in consecutive patients with PPLs 8 to 50 mm in diameter. All procedures were performed with the guidance of virtual bronchoscopic navigation (VBN) and radial endobronchial ultrasound (rEBUS), but without fluoroscopy. Patients were randomized to UTB group, TB with guide sheath (GS) group, TB without GS group. A small forceps was used in UTB group and TB-GS group, while a standard forceps was used in TB-non-GS group. <bold>Results:</bold> A total of 578 patients were enrolled and 532 were finally analyzed at five centers in China. The average lesion size was 27.4±8.8 mm. UTB can reach more distal bronchi than TB (median fourth- vs. third-generation, P<0.001). The diagnostic yields were 82.2% (143/174), 83.2% (149/179), 83.8% (150/179) for UTB group, TB-GS group, and TB-non-GS group, respectively (P=0.92). The bleeding rate was 1.7% (3/174), 3.9% (7/179), and 11.2% (20/179) in the respective group (P<0.001); and there was no pneumothorax. <bold>Conclusions:</bold> UTB is an effective and safe tool for the diagnosis of PPLs without fluoroscopy, its diagnostic yield is non-inferior to TB using small forceps with a GS or standard forceps.