Measuring the success of transbronchial needle aspiration in everyday clinical practice

Trans-bronchial needle aspiration (TBNA) is a simple, safe technique that can be performed without additional resources in any centre with a bronchoscopy service. It provides rapid diagnostic information in malignant and benign conditions and staging information in non-small cell lung cancer (NSCLC) and may avoid the delays, risks, in-patient stay and financial implications associated with surgical exploration of the mediastinum. Despite this, centres have been slow to adopt the technique. This may be due to the lack of clarity about the clinical success of TBNA in everyday clinical practice and the absence of a single valid measurement of clinical utility for TBNA against which to audit.

We undertook a retrospective analysis of all TBNA carried out at Nottingham City Hospital since the service began. "Success" was carefully and strictly defined. The influences of various factors on the likelihood of a successful outcome were analysed.

Fifty percent (71/142) of patients undergoing TBNA received an exact histological diagnosis whilst in 72% (97/134) of patients in whom a final diagnosis was made, TBNA results correctly predicted malignant versus benign conditions. We defined the former, more stringent, outcome measure as "success--exact". This outcome was not significantly affected by patient age or gender, lesion size or position, experience of the bronchoscopist or number of aspiration attempts. Final diagnosis strongly influenced "success--exact" with NSCLC 6.5 times and small cell lung cancer 28.5 times more likely to yield a diagnostic sample than benign conditions.

TBNA should be used as a standard first line invasive investigation for diagnosis of mediastinal lymphadenopathy or submucosal endobronchial disease. The stringent outcome defined in this study as "success--exact" is simple for clinicians and patients to understand and would be a useful definition to standardise audit and future research.