The Use of a Linear Ultrasound Bronchoscope for Transesophageal Staging of Lung and Esophageal Cancers

Abstract

Background: Radial and linear endoscopic ultrasound (EUS) scopes are used to assess for lymphadenopathy and metastases in patients with esophageal and lung cancers. It is often difficult to pass a standard EUS scope in patients with an esophageal mass or a malignant esophageal stricture, even after dilation. A linear endobronchial ultrasound (EBUS) scope is smaller in diameter than a standard EUS scope. Aim: To review our experience using a linear EBUS scope within the esophagus to detect and FNA lymphadenopathy and metastases in patients with esophageal cancer in whom a standard EUS scope could not be passed and in patients with lung cancer. Methods: We conducted a retrospective review of the Medical University of South Carolina (MUSC) EUS and OASIS databanks for patients in whom a linear EBUS scope (Olympus, BF-UC160) was used for staging of known or suspected lung and esophageal cancers. Results: There were 8 patients in whom the linear EBUS scope was used for transesophageal imaging; 2 patients had esophageal cancer, 6 patients had known or suspected lung cancer and had transbronchial EBUS by a pulmonologist in conjunction with our exam. The EBUS scope could not be passed down the esophagus of 1 esophageal cancer patient even after dilation to 10 mm; a 12 Mhz catheter probe had to be used. The other esophageal cancer patient was dilated to 11 mm with subsequent successful passage of the EBUS scope. Overall, there were 7 patients in whom the EBUS scope was passed down the esophagus. In 100% of these patients, the celiac axis, subcarinal space, A-P window, left adrenal and left lobe of the liver were successfully viewed. Benign appearing lymph nodes were detected in all of these patients; FNA of suspicious subcarinal lymph nodes was performed in 1 patient, with adequate specimen. Both a linear EBUS scope and a 12 Mhz catheter probe were used in 1 patient with detection of 1 oval, hypoechoic 6 mm peri-tumoral lymph node with the EBUS scope that was not seen with the catheter probe. Limitations included having to pass the EBUS scope over a guidewire in the patient with an esophageal mass and the lack of water/air function. Conclusion: A linear EBUS scope was successfully used in the esophagus to view the celiac axis, subcarinal space, A-P window, left adrenal and left lobe of the liver in patients with lung cancer and in patients with esophageal cancer in whom a standard EUS scope could not be passed, though technically difficult. Visualization of the liver with the EBUS scope was inadequate in all patients, limiting its usefulness, but it is more desirable than using a catheter probe because it allows for FNA when needed.