Outcomes of non-diagnostic endobronchial ultrasound guided tranbronchial needle aspiration

Introduction: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a procedure, which is increasingly available for the evaluation of mediastinal lymph nodes and masses. Although it has been proved to be a helpful diagnostic procedure for mediastinal node metastasis, the value of negative EBUS is not clear. Methods: Retrospective review of the EBUS procedures. Results: A total of 106 EBUS procedures were attempted over 18 months, 105 procedures were completed, 1 patient did not co-operate and the procedure was abandoned. All the procedures were done with local anaesthesia and conscious sedation. In 4, EBUS did not show any significantly enlarged lymph nodes, so no samples were taken. The mean age of the patients was 65.6 yrs (range 22-87 years), with 68 males (64.2%). In 97 of 101 lesions sampled (97%), EBUS-TBNA yielded representative samples. In 51 cases the EBUS sample yielded diagnosis and were considered true positive. In the rest 50 cases the samples were non-diagnostic, out of which 19 were true negative based on either mediastinoscopy or follow up. Four were false negative. The remaining 27 need follow up to know whether they are true negative or otherwise. In the 74 cases the overall sensitivity, specificity, positive predictive value and negative predictive value were 92.7%, 100%, 100% and 82.6% respectively. Conclusions: EBUS-TBNA yielded diagnosis in half of the cases. In majority of patients with non-diagnostic EBUS, based on multi-disciplinary team review it was decided to follow up rather than directly proceed with mediastinoscopy or surgery because of either high risk for surgery or low clinical probability of malignancy.