Rationale: Endobronchial ultrasound (EBUS) combined with a guide sheath (GS) as an instrument for confirming the proximity of the bronchoscope and its relationship to the lesion can increase the diagnostic yield when conducting transbronchial lung biopsy of peripheral pulmonary nodules (PPNs). A novel electromagnetic navigational bronchoscopy (ENB) system comprising a thinner locatable sensor probe as a guidance instrument was developed to be suitable for a thin bronchoscope with a working channel 2 mm in diameter. The diagnostic efficacy of EBUS-GS with or without this ENB system has not been confirmed. Objectives: To compare the diagnostic value and safety of EBUS-GS with or without the ENB system for diagnosing PPNs. Methods: A prospective, multicenter, randomized controlled clinical trial was designed and conducted at three centers. Patients with PPNs suspected to be malignant were enrolled and randomly assigned to the ENB-EBUS-GS group or the EBUS-GS group. The primary endpoint was the diagnostic yield in each group. The secondary endpoint was the procedural time and other factors affecting diagnostic yield. The safety endpoint was procedural complications. Results: Four hundred participants were enrolled from July 2018 to October 2019, and 385 patients were analyzed, 193 in the ENB-EBUS-GS group and 192 in the EBUS-GS group. The mean nodule size was 21.7 ± 5.3 mm. The diagnostic yields were 82.9% (95% confidence interval [CI], 77.6-88.2%) in the ENB-EBUS-GS group and 73.4% (95% CI, 67.2-79.7%) in the EBUS-GS group. The difference between the two groups was 9.5% (95% CI, 2.6-16.3%), with an adjusted difference of 9.0% (95% CI, 2.3-15.8%) after adjusting for the stratification factors and center. The time to find lesions in the ENB-EBUS-GS group was shorter than in the EBUS-GS group (213.2 ± 145.6 vs. 264.8 ± 189.5 s; P = 0.003). Intraoperative hemorrhage occurred 3.6% of subjects in the ENB-EBUS-GS group and 3.1% in the EBUS-GS group, without significant differences between the two groups. Conclusions: The novel ENB system combined with EBUS-GS demonstrated improved ability to locate PPNs, achieving a high diagnostic yield for PPNs compared with EBUS-GS alone in a safe and efficient procedure. Clinical trial registered with www.clinicaltrials.gov (NCT03569306).
Keywords: electromagnetic navigation bronchoscopy; endobronchial ultrasound; guide sheath; lung cancer; peripheral pulmonary nodule.