A new technique in endoscopic ultrasonography of the upper gastrointestinal tract

Endoscopic ultrasonography (EUS) of the upper GI tract was unsuccessful in 42 out of 274 patients (15%) due to inaccurate guidance of the probe to small, shallow lesions, or to difficulty in clearly demonstrating the surrounding layer structure and boundary of the lesion. We applied the saline injection technique in these 42 patients. Saline was injected into the submucosal layer of the esophagogastric wall. The ultrasonographic image of adjacent saline accurately guided the probe to the lesion. Injected saline enabled the mucosal layer to be distinguished from the muscularis propria surrounding the lesion and provided clear ultrasonographic imaging of the boundary between the lesion and the surrounding layer structure. This new method was found to be effective in 38 out of 42 patients in whom EUS was unsuccessful. A study comparing the depth of tumor invasion diagnosed by the saline injection technique with histological findings obtained in 12 cases showed good correlation. These results indicate that the saline injection technique would seem to be very useful as an adjuvant to conventional EUS.