Impact of Endobronchial Ultrasound Guided Transbronchial Needle Aspiration on Diagnostic Yield of Bronchoscopy in Patients with Mediastinal Lymph Node Enlargement.

Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) had an enormous impact on the current advancement in diagnostic bronchoscopy. The aims of the present study were: (1) to evaluate the added value of EBUS-TBNA to routine diagnostic bronchoscopy performed in patients with mediastinal lymph node enlargement and (2) to identify factors that affect the diagnostic yield of EBUS-TBNA. We retrospectively analyzed 712 EBUS-TBNA procedures out of the 4081 bronchoscopies performed in the years 2009-2014. The number of EBUS-TBNA procedures increased from 61 (8.8 % of all bronchoscopies) in 2009 to 160 (21.4 %) in 2014. In 625 (87.8 %) patients adequate cytological material was obtained. Based on cytological examination of EBUS-TBNA aspirates, specific diagnosis was made in 367 (51.5 %) patients. The forceps biopsy of endobronchial lesions provided specific diagnosis in only 204 (28.6 %) patients. The percentage of patients with EBUS-TBNA based diagnosis increased steadily from 34.4 % in 2009 to 65.0 % in 2014 (p < 0.0001). The median lymph node diameter in patients with positive EBUS-TBNA findings was 20 (IQR 15-30) mm and was significantly larger than that in patients with negative EBUS-TBNA results (15 (IQR 10-20) mm, p = 0.0001). The highest diagnostic yield (78.5 %) was found in patients with lymph node dimension between 31 mm and 40 mm. We conclude that EBUS-TBNA is a valuable diagnostic method in an unselected group of patients with mediastinal lymph node enlargement. The percentage of positive EBUS-TBNA diagnoses is related to lymph node dimensions. The overall efficacy of EBUS-TBNA improves with increasing years of experience.