EBUS- TBNA-Initial Experience from a Tertiary Care Center in Southern India

Introduction: Conventional trans bronchial needle aspiration is associated with a low diagnostic yield in mediastinal adenopathy. Ultra sound guidance improves the diagnostic yield in these cases. Though linear probe EBUS was introduced in southern India as early as 2008, there is a dearth of literature in South Indian population on the utility of this diagnostic modality. Aim: To analyse the diagnostic yield, sensitivity, specificity of real time endo bronchial ultrasound guided trans bronchial needle aspiration (EBUS-TBNA). Materials and Methods: A prospective observational study was carried out from April 2014 to October 2016. Patients referred for evaluation of medisatinal lymphadenopathy were evaluated with computed tomography of the thorax and EBUS-TBNA was done under conscious sedation. Rapid on site examination was done. A sample that was positive for malignant cells/granuloma was considered to be diagnostic. A non-diagnostic procedure was followed up with definitive surgery or a six month clinicoradialogical follow up. Results: The study included 78 patients (48 males) with mean age 55.9 years. EBUS-TBNA detected 237 enlarged mediastinal nodes with average diameter of 20.48 +/- 8.55 mm. A total of 125 lesions were sampled of which sub carinal lymph node was the most common station (44.8%). Average of 1.6 lymph nodes was sampled per patient with 2.92 passes per lymph node. The procedure had a diagnostic yield of 91.02%, with sensitivity of 89.55% (79.65-95.70%), specificity of 100% (71.51-100%), Negative likelihood ratio of 0.10 (0.05-0.21), positive predictive value of 100% (94.04-100%), negative predictive value of 61.11% (32.75-82.70%). Majority of the patients were diagnosed with non small cell cancer with tuberculosis constituting the major diagnosis among the patients with clinical suspicion of a non malignant aetiology. There were no complications associated with the procedure. Conclusion: EBUS guided TBNA is a safe procedure with a good diagnostic yield. It is a useful procedure in lymph nodes which remain inaccessible by conventional TBNA or mediatinoscopy based on size or location.