Feasibility of thin convex probe EBUS scope for the diagnosis of peripheral pulmonary lesions

Despite the emergence of advanced ancillary technologies, the transbronchial method to peripheral pulmonary lesions (PPLs) remains a challenge for bronchoscopists. The objective of the study is to assess the diagnostic value and safety of a novel thin Convex Probe Endobronchial Ultrasound (TCP-EBUS) scope in transbronchial needle aspiration (TBNA) for PPLs suspicious of malignancy.

This single-center feasibility study prospectively enrolled patients with PPLs between August 2022 and January 2023. All lesions were biopsied by EBUS-TBNA using the novel TCP-EBUS scope (BF-UC290F, Olympus) and the prototype 22G aspiration needle (Vizishot2 22G, Olympus). The primary end point was the diagnostic yield.

Thirty-three subjects were evaluated, and 30 subjects were included in the final analysis. The mean patients' age was 62.4 ± 10.2 years, and 60% were male. The mean lesion size was 25.7 ± 6.8 mm, and 22 nodules were ≤30 mm. PPLs were situated adjacent to the subsegmental or sub-subsegmental bronchi (25 and 5, respectively), and the EBUS scope was advanced into segmental or subsegmental bronchi (12 and 18, respectively). Average number of punctures was 3.8 ± 1.3. Adequate specimens were obtained in all 30 (100%) of the cases. The overall diagnostic yield was 90% (27/30). No serious adverse events were observed.

The TCP-EBUS has decent accessibility to more distal intrapulmonary lesions. TCP-EBUS-TBNA is a safe real-time procedure with a high sensitivity for malignant PPLs in the inner two-thirds of the lung, irrespective of the presence of a bronchus sign.