To the Editors:
In the March 2005 issue of the European Respiratory Journal, three original articles by Annema et al. 1, Caddy et al. 2, and Rintoul et al. 3, accompanied by an editorial by Vilmann and Larsen 4, appeared on ultrasound (US)-guided endoscopic needle aspiration of mediastinal lymph nodes. All of these articles unquestionably contribute to the growing body of evidence that sampling of lymph nodes or masses in the chest using an endoscopic tool has a high yield and is safe. This letter was prompted by the new meaning of the abbreviation “EUS”. The term endoscopy in the chest comprises the four entities: bronchoscopy, oesophagoscopy, mediastinoscopy and thoracoscopy. When talking about endoscopy only, the access to the chest is not defined. Likewise, an US-guided procedure is linguistically coupled with the route used, such as the transthoracic (TT), endobronchial (EB), or oesophageal (E) route. When performing a bronchoscopy, the correct term is EBUS, when oesophagoscopy is used it is EUS. Earlier articles on EUS used the letter “E” correctly for “oesophageal” or even better “transoesophageal” 5, but, more recently, it has been used for “endoscopic” 1–3, 6, which is incorrect. Sadly, even leading journals have started to accept this change. It is thus not surprising that in the article by Rintoul et al. 3, the title had to start with a misnomer: “Endobronchial and endoscopic ultrasound-guided real-time fine-needle aspiration for mediastinal staging”. Is endobronchial not endoscopic?
Unfortunately, the problem is not only a semantic one. Highjacking the “E” in EUS for “endoscopic” implies that “oesophageal” can be equated with “endoscopic”, insinuating that the other endoscopic techniques are inferior. In the article by Annema et al. 1, which uses oesophageal US-guided sampling of mediastinal nodes for the diagnosis of sarcoidosis, it is stated in the conclusion that endoscopic (they mean oesophageal) US-guided ( = EUS) fine-needle aspiration (FNA) should be the next step after a negative bronchoscopy. This conclusion was based on the fact that EUS had an impressive yield of 82% in sarcoidosis patients after a negative bronchoscopy. In their series of 51 patients, however, only 36 had undergone bronchoscopy, and, surprisingly, the reader is not told what was done at bronchoscopy! Bronchoscopy using EBUS-transbronchial needle aspiration (TBNA) might have resulted in the same yield as was obtained by EUS-FNA. To maintain their conclusion, the authors should have compared EUS-FNA prospectively with EBUS-TBNA.
The most important issue in the evolving role of various sampling techniques, however, is to differentiate between situations when the available endoscopic procedures are complementary and when they are competitive. A subcarinal lymph node will be successfully sampled by any endoscopic method; thus, they all compete. Paraoesophageal lymph node stations eight and nine are the undisputed domains of EUS-FNA, just as anterior tracheal or right hilar nodes are the domains of EBUS-TBNA. The choice of the tool to be used lies in the accessibility of the tissue to be sampled, and, among competitive methods, the least invasive one should be chosen. When sampling for benign disease, any tissue delivering the diagnosis is sufficient. In bronchogenic carcinoma, however, diagnosis and endoscopic staging can often be combined 7. In this situation, bronchoscopy should be the first procedure of choice as it can sample peripheral lesions, screen for synchronous endoscopically visible cancer, and stage all lymph nodes adjacent to the tracheobronchial tree as well.
The evolving consensus, corroborated by the current three studies 1–3, is that the role of both EBUS-TBNA and EUS-FNA will increase, whereas mediastinoscopy will substantially decrease, at least in centres that have the skills and the financial resources to offer EBUS-TBNA and EUS-FNA.
In order to discuss the relative merits of the “new kids on the block”, i.e. endobronchial ultrasound-guided transbronchial needle aspiration and oesophageal ultrasound-guided fine-needle aspiration, let's start by getting the terminology right.
- © ERS Journals Ltd
