Comparison of the Thin Convex Probe Endobronchial Ultrasound Bronchoscope to Standard EBUS and Flexible Bronchoscope: A Cadaveric Study

Background: Convex probe endobronchial ultrasound (CP-EBUS) with transbronchial needle aspiration (TBNA) is used to sample mediastinal and hilar lymph nodes and is considered a gold standard for mediastinal staging of lung cancer. Current technology is limited in ability to sample lesions located away from the mediastinum. The aim of this study was to evaluate the range of a new thin convex probe EBUS prototype in a cadaveric model and compare its accessibility into distal airways to that of a standard flexible and CP-EBUS bronchoscope using a cadaveric model. Methods: Three separate bronchoscopes were used and compared: standard bronchoscope (Olympus BF-H190), linear CP-EBUS bronchoscope (Olympus BF-UC180F), and the thin CP-EBUS bronchoscope. (Olympus BF-Y0055). Each bronchoscope was inserted sequentially into a male and female cadaver. The number of bronchial generation accessible was recorded and compared using fluoroscopy. A polymer was created and inserted into various airways to simulate lesions, which were then localized and sampled. Results: The TCP-EBUS prototype demonstrated improved accessibility of distal airways when compared to CP-EBUS bronchoscope. In the male and female cadaver the TCP-EBUS bronchoscope accessed an additional generation and in most instances accessed the same distal airways as a standard bronchoscope. Conclusion: The thin convex probe-EBUS bronchoscope can extend further into the distal airways than the traditional CP-EBUS bronchoscope and can achieve a reach similar to a standard bronchoscope, thus allowing the potential to bring real-time biopsy capability to areas of the lung that currently cannot be reached by standard convex probe-EBUS.