Comparison of different transbronchial biopsy sampling techniques for the diagnosis of peripheral pulmonary lesions with radial endobronchial ultrasound-guided bronchoscopy: A prospective study

Abstract

© 2020 The Japanese Respiratory Society Background: Data regarding the transbronchial biopsy (TBB) techniques in radial endobronchial ultrasound (R-EBUS)-guided bronchoscopy are limited. The purpose of this study was to compare three R-EBUS-guided TBB techniques for the diagnosis of peripheral pulmonary lesions (PPLs). Methods: A prospective pilot study was conducted including 90 patients with positive bronchus sign PPLs, who underwent R-EBUS-guided TBB. TBB techniques were performed in all patients using small biopsy forceps with a guide sheath (GS). These samples were submitted for both cell block histology (CB) and conventional histology (SB). Standard biopsy forceps were used to collect further samples that were submitted for conventional histology (LB). The diagnostic yields of the three techniques were compared. Results: The mean diameter of the PPLs was 25.5 ± 8.2 mm and the final diagnoses included 70 malignant and 20 benign lesions. The overall diagnostic yield of R-EBUS-guided bronchoscopy was 82.2%. Although the difference was not statistically significant, CB provided the highest yield of the three TBB techniques: 68.9%, 65.6%, and 62.2% for CB, SB, and LB, respectively (P = 0.20). When the GS was removed and standard biopsy forceps were introduced, misplacement (detected by fluoroscopy) was observed in 24 cases, and LB provided a diagnosis in 11 cases. PPLs ≤20 mm were associated with misplacement (P = 0.003). After the exclusion of misplaced cases, the diagnostic yields were 69.7%, 71.2%, and 68.2% for CB, SB, and LB, respectively (P = 0.65). Conclusions: Neither the size of biopsy forceps nor the histology process affected the diagnostic yield of R-EBUS-guided bronchoscopy.