Convex-probe Endobronchial Ultrasound: A Decade of Progress

Ever since the invention of the flexible bronchoscope, perhaps no other innovation in the field of interventional pulmonology has caused so much excitement the world over, as the convex probe endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA). While it took over a decade from 1992 to 2004 for the radial EBUS to evolve into the commercial convex probe EBUS scope, another exciting decade has gone by with the technology being thoroughly researched and appraised. The current evidence suggests that EBUS-TBNA can replace mediastinoscopy as the first investigation in the mediastinal staging of lung cancer. The use of EBUS-TBNA has been extended to several other areas including the diagnosis of undefined mediastinal lymphadenopathy, evaluation of intra-parenchymal lesions and others. In fact, EBUS-TBNA is the preferred modality for accessing mediastinal lesions in contact with the airways. The procedure not only has a high diagnostic efficiency (80%-90% for most indications) but is also safe compared to alternative options, such as image-guided fine needle aspiration and mediastinoscopy in the diagnosis of mediastinal lymphadenopathy. Apart from the traditional use of EBUS to perform TBNA, the last decade has seen the evolution of its transoesophageal use, development of novel EBUS-TBNA needles to obtain better histological specimens and a smaller EBUS scope. This review summarises the developments made in this field over the years since its inception.