INTRODUCTION: Endoscopic Ultrasound (EUS) is a new technology that enables detailed imaging of the GI tract and improved staging of GI malignancies. In previous studies, EUS has been used to evaluate patients with Barrett's esophagus. These studies reported that EUS was not helpful in detecting early esophageal cancer or following dysplasia in these patients, since the marked inflammation seen was difficult to differentiate from tumor or from other causes such as erosive esophagitis. Recently, a new catheter based ultrasound probe (CBUSP) has been developed that provides improved resolution and imaging of the GI tract. The purpose of this study was to evaluate the role of this CBUSP in Barrett's esophagus. METHODS: 15 patients (7 - Barrett's esophagus, 5 - normal controls) underwent examination of the esophagus with a CBUSP and conventional EUS. All patients were prospectively evaluated and data collected regarding the endoscopic extent of Barrett's, wall thickness, presence of other ultrasound imaging abnormalities (i.e., a mass, lymph nodes, varices, etc.) and comparison data for CBUSP vs. conventional EUS. The probes are manufactured by Microvasive (Natick, MA) and are 6.2 Fr in diameter operating at 20 MHz. These probes are driven by a Hewlett-Packard console. RESULTS: All 15 patients successfully underwent EUS and CBUSP of the esophagus. In the normal controls, the average thickness of the distal third of the esophagus was.365 cm. In the patients with Barrett's esophagus the average thickness in the distal esophagus at the level of Barrett's epithelium was 0.692 cm. The CBUSP provided improved resolution of the esophageal wall and showed detailed imaging of the Barrett's epithelium as diffuse thickness of the entire wall layer. A peculiar finding of marked thickening of the muscularis propria was noted in the Barrett's group. These detailed findings were not seen with conventional EUS. Furthermore, no masses were seen. Only 1 of the 7 Barrett's esophagus patients had low grade dysplasia and none had high grade dysplasia. There were no catheter related complications or malfunctions during these examinations. However, the lack of a balloon makes this CBUSP difficult to image without insufflation of water. SUMMARY: CBUSP provided detailed imaging of the esophageal wall in patients with Barrett's esophagus. In these patients the esophageal wall had a greater thickness than normal controls. This finding was in agreement with previous studies using conventional endoscopic ultrasound in patients with Barrett's esophagus. CBUSP also provided enhanced resolution and in 1 patient a lymph node was seen that appeared benign. CONCLUSIONS: 1) CBUSP of the esophagus is safe and feasible but for now appears to be limited in imaging patients with Barrett's esophagus. 2) A peculiar finding of marked thickening of the muscularis propria in patients with Barrett's esophagus was seen on CBUSP. 3) Further studies in patients with high grade dysplasia and probe modifications are needed.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging