[Endobronchial ultrasonography with distance by thin bronchoscopy in diagnosing peripheral pulmonary lesions]

To evaluate the efficacy, safety and factors related to diagnostic yield of transbronchial biopsy (TBB) using thin bronchoscopy to endobronchial ultrasonography with distance ( EBUS-D) for peripheral pulmonary lesions (PPLs).

Between October 2013 to September 2014, 117 patients [67 males and 50 females, aged (62.2 ± 10.9 ) years] underwent EBUS-D-guided TBB for the diagnosis of PPLs [mean size (22.9 ± 9.5) mm] and their medical records were retrospectively reviewed and analysed. EBUS was performed using a 4-mm thin bronchoscope and a 1.4 mm radial ultrasound probe. EBUS-D was to measure the distance between the PPL to the target bronchial orifice or to the outer orifice of the working channel of the bronchoscope when an EBUS image of the PPL was observed, and then the biopsy forceps were advanced to this measured distance and biopsy followed.

The visualization yield of EBUS was 77.8% (91/117). The overall diagnostic yield was 65.0% (76/117) by EBUS-D-guided TBB, and the diagnostic yield in malignant and benign lesions was 75.0% (66/88) and 34.5% (10/29), respectively. The diagnostic yield for PPLs > 20 mm in diameter was significantly higher than that for those ≤ 20 mm in diameter (78.7%,48/61 versus 50.0%, 28/56) (χ² 10.56, P=0.001). There was no significant difference in diagnostic yield between lobar distribution (right upper lobe 61.8%, 21/34; right middle lobe 91.7%, 11/12; right lower lobe 59.1%, 13/22; left upper lobe 57.1%,12/21; lingula 80.0%,4/5; left lower lobe 65.2%,15/23) (χ² = 5.31, P=0.38). The diagnostic sensitivity was only 18.2% for lesions close to visceral pleura with mean size ≤ 20 mm. Sometimes radial probe could pass through the PPL without resistance, and the diagnostic yield was lower in this situation. Complications including bleeding and chest pain recovered spontaneously.

Using EBUS-D-TBB with a thin bronchoscope, the vast majority of peripheral pulmonary lesions could be identified. The modality was far more cost-effective than EBUS-GS and there were no significant complications associated with this procedure. Lesion size, connection to the visceral pleura and radial probe through the lesion influenced the diagnostic yield.