CURRENT ENDOSONOGRAPHIC POSSIBILITIES IN THE UPPER GASTROINTESTINAL-TRACT

Almost 15 years after its introduction endosonography is an important technique in a wide range of gastrointestinal diseases. Two types of dedicated echoendoscopes are commercially available each with their own advantages. Thinner instruments with higher resolutions, that will go through a normal endoscope are currently in development. With these probes differentiation between T1 and T in situ will be possible in the near future. Characterization of 'submucosal' lesions in the upper gastrointestinal tract is a field in which ES is the most reliable technique for determining the origin of these lesions. Also submucosal vessels are easily visualized and ES is acquiring an important role in the investigation of portal hypertension. ES is the most accurate staging technique for oesophageal and gastric carcinoma as well as for gastric lymphoma. T- and N-staging results are superior to CT scanning, although ES is not very reliable in individual lymph nodes. Therefore a lot of effort is put into obtaining cytological samples from lesions outside the gastrointestinal tract. It is now possible to get cytological proof of mediastinal lymph nodes through ES-guided fine needle aspiration biopsy. It seems that low grade malignant gastric lymphomas show a typical picture on ES, which may help in selecting treatment. The future will bring us higher resolution images and three-dimensional reconstruction is already being investigated. This last technique will probably become a standard preoperative investigation in oesophageal carcinoma before the century is over. © 1994.