Endoscopic sonography of the upper gastrointestinal tract and pancreas.

Endoscopic sonography is a new approach to visualizing upper gastrointestinal lesions. The sonographic device, which incorporates a sonographic transducer mounted on a standard fiberoptic endoscope, makes it possible to obtain high-resolution images of mucosal and mural lesions of the gastrointestinal tract, as well as of adjacent masses. This technique has substantially improved preoperative staging of esophageal and gastric cancers. In addition, high-resolution sonographs of the pancreas can be obtained without degradation by overlying bowel gas, making identification of small, previously occult lesions of the pancreatic head possible. We have used endoscopic sonography in staging esophageal, gastric, and pancreatic cancers in more than 200 patients. This essay illustrates our experience with this new technique.