First in Human Evaluation of a Novel Thin Convex Probe Endobronchial Ultrasound System.

Introduction: The incidence of pulmonary imaging abnormalities continues to increase. While standard convex probe endobronchial ultrasound bronchoscope (CP-EBUS) is safe and accurate, it has limited reach through smaller bronchi. Olympus BF-Y0069 thin convex probe EBUS (TCP-EBUS) has a smaller diameter and improved angulation. We assessed the safety and feasibility of the TCP-EBUS to evaluate lesions not accessible with CP-EBUS.

Methods: A single-center, prospective, pilot study evaluating TCP-EBUS enrolled patients undergoing bronchoscopy for lesions within the inner two-thirds of the lung. Patients underwent CP-EBUS to attempt visualization and biopsy. If unsuccessful, TCP-EBUS was used. Safety, lesion characteristics, and pathology results were collected.

Results: Fifty-one patients were enrolled with multiple lesion locations and no adverse safety events with TCP-EBUS. Seven cases (13.7%) were omitted as the target lesion was visualized by CP-EBUS and TCP-EBUS. CP-EBUS failed to provide biopsy for 44 cases. CP-EBUS visualized 7/44, however, was unable to biopsy. TCP-EBUS visualized 36/44 (81.8%) lesions and biopsied 27/44 (61%) lesions. 8/44 (15.7%) lesions could not be visualized with either device. Median lesion size biopsied with CP-EBUS was 41 mm (IQR: 22-48). Median size of lesions visualized with TCP-EBUS was 20 mm (IQR: 15.3-38), range 8-70. The median distance from the main carina was 62 mm (IQR: 60-89) for lesions biopsied with the CP-EBUS and 63.3 (IQR: 48.5-78.8) for TCP-EBUS. While average distances from main carina were similar in both groups, the furthest lesion TCP-EBUS visualized was 120 mm from the carina compared to 100 mm with CP-EBUS.

Conclusions: The use of TCP-EBUS was safe and effective without observed patient-associated complications, and it provided real-time ultrasonographic visualization and biopsy of lesions not accessible with CP-EBUS.