Utility and safety of sole electromagnetic navigation bronchoscopy under moderate sedation for lung cancer diagnosis

Background: Electromagnetic navigation bronchoscopy (ENB) is an emerging technique for diagnosing pulmonary lesions. However, limited data is available on its sole utility under a least invasive setting without general anesthesia. We aimed to evaluate the diagnostic performance and safety of sole ENB under moderate sedation for diagnosing pulmonary lesions suspicious for lung cancer and to determine clinical factors associated with a better diagnostic yield. Methods: We performed a retrospective analysis of consecutive patients who underwent sole ENB under moderate sedation for lung lesion biopsy between August 2016 and June 2021 at Seoul National University Bundang Hospital, a tertiary center in South Korea. Diagnostic yield of the ENB-guided biopsy, safety endpoints defined by the incidence and severity of associated complications, and factors associated with higher diagnostic yield were evaluated. Results: A total of 94 patients were evaluated. The final diagnostic yield of ENB was 81.5% (75/92), excluding two indeterminate cases. The diagnostic yield ranged from 79.8% to 81.9% assuming all indeterminate cases were false-negatives (79.8%) and true-negatives (81.9%). The sensitivity and specificity for malignancy were 77.6% (ranging from 75.6% to 77.6%) and 100%, respectively. Any-grade pneumothorax occurred in 4.3% of the patients, and 2.1% developed pneumothorax requiring additional intervention. Multivariable analyses identified the presence of a class 2 bronchus sign as the only significant predictor for a higher diagnostic yield (odds ratio =4.83, 95% CI: 1.16-20.12). The diagnostic yield of ENB among those with class 2 bronchus sign was 89.8% (53/59). Conclusions: Sole ENB under moderate sedation for diagnosing pulmonary lesions displayed a good diagnostic yield and safety profile, thus confirming its utility in a least-invasive setting. Moreover, sole ENB could be possibly be superior to transthoracic needle aspiration for diagnosing lesions with class 2 bronchus sign accounting for similar yields and lower complication rates.N