The Evaluation of the Diagnostic Yield and Complications Associated with Bronchoscopy via Endobronchial Ultrasound with a Guide Sheath.

Objective Endobronchial ultrasound with a guide sheath (EBUS-GS) is used to accurately position a bronchoscope in lung lesions using a guide sheath. Previous studies have focused on diagnostic success as the endpoint. The achievement of 'within' defined as reaching the lesion, is considered crucial in EBUS-GS procedures. This study investigated cases wherein 'within' is likely to be achieved and cases that can be diagnosed after achieving 'within'. Methods This retrospective study evaluated 258 bronchoscopic examinations using EBUS-GS. We analyzed the relationship between patient background, lesion size and characteristics, achieving 'within', definitive diagnosis after achieving 'within', and complications. Results A multivariate analysis revealed that a lesion size ≥20 mm [odds ratio 12; 95% confidence interval (CI): 6.0-21; p<0.01] and the presence of solid components (odds ratio 13; 95% CI: 1.3-120; p=0.03) were significantly associated with achieving a "within" status. Among cancer cases, lesions ≥20 mm had a higher diagnostic yield after achieving "within" compared with smaller lesions (odds ratio 4.23; 95% CI: 1.38-12.9; p=0.01). The occurrence of complications was also associated with lesion size ≥20 mm (odds ratio 2.7; 95% CI: 1.02-6.9; p=0.045). Conclusion Lesion size ≥20 mm and the presence of solid components were key factors associated with achieving "within" during bronchoscopy via EBUS-GS. Larger lesions were linked to a higher rate of definitive diagnosis. Overall, lesion size played a major role in improving diagnostic performance, both in achieving "within" and in successfully obtaining a diagnosis once "within" was achieved.