Supplementary Material for: A Randomized Clinical Trial of Flex 19G Needles versus 22G Needles for Endobronchial Ultrasonography in Suspected Lung Cancer

Background: A flexible 19-gauge (Flex 19G) needle has been developed for endobronchial ultrasonography. Objectives: We aimed to evaluate quantitative and qualitative specimen characteristics of Flex 19G in a randomized controlled setting for patients with suspected lung cancer. Methods: We undertook a single-center, randomized, controlled trial. A computer-generated randomization assigned all enrolled patients 1: 1 to undergo endobronchial ultrasonography using a Flex 19G or a 22-gauge (22G) needle for lymph node tissue sampling. Pathologists were blinded to the group assignment. The primary end point was histological tissue core procurement. The secondary end points were diagnostic yield, specimen bloodiness and overall quality, tissue surface area and performance for next-generation sequencing (NGS), and procedure-related complications. Results: Between June 2016 and February 2017, we randomly allocated a total of 78 patients: 39 patients to Flex 19G and 39 patients to 22G. No superiority in tissue core procurement was observed for Flex 19G compared to 22G (67 vs. 72%, p = 0.81). No significant difference was observed in diagnostic yield and overall specimen quality, but transbronchial needle aspiration specimens by Flex 19G were bloodier and had a larger tissue surface area. NGS was successful for clinically relevant genes in 96% and for all 26 genes tested in 81% of the samples. There was no difference in clinically relevant complications. Conclusions: No superiority is observed for Flex 19G in histological tissue core procurement rate. The Flex 19G needle could be considered when a larger tissue surface is of special interest.