Advantages of a larger working channel diameter of ultrathin bronchoscope in cone-beam computed tomography-guided transbronchial biopsy for diagnosing peripheral lung lesions.

Background And Objective: Cone-beam computed tomography (CBCT)-guided transbronchial biopsy (TBB) using an ultrathin bronchoscope (UTB) under virtual bronchoscopic navigation (VBN) is a useful method for diagnosing peripheral pulmonary lesions. A 1.2 mm working channel UTB (SC-UTB) and a 1.7 mm working channel UTB (LC-UTB) are available, with the latter allowing radial endobronchial ultrasound (R-EBUS). The aim of this study was to compare the diagnostic yield of CBCT-guided TBB under VBN using SC-UTB and LC-UTB with R-EBUS.

Methods: Patients with peripheral pulmonary lesions of ≤ 30 mm were included. Lesions with unidentifiable bronchi on CT scans were excluded. The UTB and biopsy forceps were advanced to the target bronchus under VBN and 2D-fluoroscopy. For cases using SC-UTB, CBCT was performed with forceps inserted. In cases using LC-UTB, CBCT was performed with forceps inserted after inserting the R-EBUS probe. The outcomes were compared between the two groups.

Results: SC-UTB was used in 89 patients, and LC-UTB with R-EBUS in 68 patients. The diagnostic yield was 64.0 % and 79.4 % in cases using SC-UTB and LC-UTB with R-EBUS, respectively, showing a significantly higher diagnostic yield with the latter (p = 0.036). Additionally, the proportion of type 1 images on the primary CBCT (forceps tip within the lesion) significantly increased (31.5 % vs. 50.0 %; p = 0.019), and the proportion of re-navigation after the primary CBCT decreased (47.5 % vs. 20.6 %; p = 0.001) in the LC-UTB with R-EBUS group.

Conclusion: In CBCT-guided TBB using UTB for peripheral pulmonary lesions, LC-UTB with R-EBUS demonstrated a higher diagnostic yield compared to SC-UTB. Conference presentation: none.