Using the Endoscope for Endobronchial Ultrasound in the Esophagus

Summary

Transesophageal ultrasound (EUS-B) is a safe and feasible procedure using the echoendobronchoscope (EBUS) in esophagus and stomach. After identifying six anatomical landmarks, additional structures can be identified and biopsied, sparing subsequent diagnostic sessions. Thus, EUS-B is an ideal continuation of bronchoscopy and EBUS in diagnosing lung cancer and other diseases.

Abstract

EUS-B is a procedure using the echoendobronchoscope in the esophagus and stomach. The procedure is a minimally invasive, safe, and feasible approach that pulmonologists can use to visualize and biopsy structures adjacent to the esophagus and stomach. EUS-B gives access to many structures of which some may also be reached by EBUS (mediastinal lymph nodes, lung or pleural tumors, pericardial fluid) while others cannot be reached such as retroperitoneal lymph nodes, ascites, and lesions in the liver, pancreas or left adrenal gland. The procedure is a pulmonologist- and patient- friendly version of the gastroenterologists' EUS using the thin EBUS endoscope that the pulmonologist already masters. Thus EUS-B training should be easy and a natural continuation of EBUS. With the patient under conscious sedation and in the supine position, the echoendoscope is introduced either through the nostril or mouth into the oropharynx. Then the patient is encouraged to swallow while the endoscope is slowly bent posteriorly and introduced into the esophagus and stomach. Using the ultrasonic image, the operator identifies the six landmarks by EUS-B and EUS: the left liver lobe, abdominal aorta (with the celiac trunk and superior mesenteric artery), left adrenal gland, and mediastinal lymph node stations 7, 4L, and 4R. Biopsies can be taken from suspected lesions under real-time ultrasonographic guidance- fine needle aspiration (EUS-B-FNA) using a technique similar to that used with EBUS-TBNA. The biopsy order is M1b-M1a-N3-N2-N1-T (M = metastasis, N = lymph node, T = tumor) to avoid iatrogenic upstaging. Pre- and post-procedural observation is similar to that of bronchoscopy. EUS-B is safe and feasible in the hands of experienced interventional pulmonologists and provides a significant expansion of the diagnostic possibilities in providing safe, fast, and thorough diagnosis and staging of lung cancer.

Introduction

Endoscopic ultrasound is a key procedure in the diagnosis and staging of lung cancer and allows safe sampling from mediastinal or hilar lymph nodes^1,2. Endoscopic ultrasound comprises endobronchial (EBUS) and transesophageal ultrasound (EUS), are considered complementary procedures².

Interventional pulmonologists are trained with the EBUS endoscope but are rarely familiar with the larger EUS endoscope (Figure 1), which requires special training to handle correctly³. EBUS and EUS are often performed by diff....

Protocol

The following protocol developed at our institution (Zealand University Hospital) follows the Danish national guidelines on human research ethics.Written and informed consent was obtained from the human subjects.

1. Preparation for EUS-B

NOTE: This procedure requires experience in performing bronchoscopy / EBUS, thus the following instruction will not include details on basic steps such as sedation, monitoring etc. which are common for bronchoscopy, E.......

Discussion

EUS-B has significantly changed the field of interventional pulmonology^2,5,6,13. EUS-B allows the pulmonologist to access lesions not reachable with EBUS, simply by using the EBUS endoscope in a new way. A patient with a central lung tumor, enlarged mediastinal lymph nodes and abnormal left adrenal gland can have all lesions sampled with one endoscope in a single interventional session, saving .......

Materials

Name	Company	Catalog Number	Comments
22 Gauge FNA needle system	Olympus Medical Systems	Vizishot
EBUS echoendoscope	Olympus Medical Systems	BF-UC190F
EVIS Exera II endoscopy tower with EVIS X1 video processor	Olympus Medical Systems	CV-1500
Lidocaine gel	Multiple (e.g. Aspen Pharma)	Xylocain 2%
Lidocaine spray	Multiple (e.g. Aspen Pharma)	Xylocaine Pump Spray