EUS-B-guided Biopsies of Lung Tumors
As researchers in endosonography, we read with great interest the paper by Steinfort et al.1 We would like to congratulate the authors for exploring the utility and safety of endoscopic ultrasound-guided biopsy using the small endobronchial ultrasound-endoscope (EBUS-endoscope) in the esophagus (EUS-B-FNA). Biopsies were taken from lung tumors with EUS-B-FNA performed by pulmonologists instead of using the larger conventional EUS-endoscope (EUS-FNA), which is often used by gastroenterologists. Currently, there is no single endoscope designed for both the trachea and the esophagus. It is already known that the additional sampling of mediastinal nodes from the esophagus (EUS) to an endobronchial approach (EBUS) results in improved loco-regional staging of patients with non–small cell lung cancer.2 In the current paper, Steinfort and colleagues1 have underlined one more reason to use the esophageal route: lung tumors can be biopsied by a pulmonologist using EUS-B-FNA, which is in accordance with conclusions in a recent systematic review and meta-analysis.3
There are potential advantages in the use of a conventional EUS scope compared with EBUS-B for the esophageal analysis of lung and mediastinal lesions. The ultrasonic window angle is larger (150 to 180 vs. 50 to 60 degrees with EBUS), the ultrasonic picture is better due to a higher resolution, small structures are better visualized, and the maneuverability of the needle is better due to an “elevator.” The disadvantage of the EUS-endoscope is that most pulmonologists are not used to it and that it requires another investment.
However, Steinfort et al1 demonstrate that the small EBUS-endoscope can be used in the esophagus (EUS-B-FNA) for taking biopsies from lung tumors instead of the large EUS-endoscope. No serious complications were seen. One of 27 patients developed a pneumothorax. There were no reports of mediastinitis, bleeding, or bacteraemia.
We agree with the authors that individual endoscopists should be trained in both EBUS and EUS-B as recommended in the guidelines.2 The learning curves for pulmonologists in EUS-B should be established as it has already been done for EUS.4 The authors mention the use of sonographic landmarks during the EUS-B procedure—similar landmarks exist for EBUS and have shown to be useful for the education and assessment of competence.5 However, it is worth mentioning that unfortunately no virtual reality EUS-B simulator exists, whereas there are several EBUS simulators. We hope that a EUS-B simulator will soon be available on the market, so we can get started with simulator-based education in EUS-B.
In conclusion, the results of Steinfort and colleagues underline that the time has come for the pulmonologists to learn and implement EUS-B to ensure that more patients will benefit from this diagnostic technique.