[The technique of laparoscopic ultrasound study in diagnostic laparoscopy].

In gastric cancer, retrogastric invasion or enlarged lymph nodes in the hilus of the spleen or at the celiac trunk can readily visualized with laparoscopic ultrasound examination (LUS). Invasion or metastases of the liver can be identified which are "invisible" with the "classic" imaging methods. In our series this led to revision of the TNM staging in 8% of 111 patients with advanced gastric carcinoma. In the staging of early pancreas cancer the standard methods of investigation, including ERCP, are unsatisfactory. Tumor localization, invasion of blood vessels and local or distal lymph node metastases cannot always be evaluated reliably. LUS promises to provide this valuable information. In carcinoma of the distal esophagus or the cardia, LUS can help to exclude small liver metastases, assess invasion of the diaphragm and evaluate the extent of enlarged intraabdominal lymph nodes, especially those at the celiac trunk. A frequent challenge/task for LUS is the exact determination of the benign or malignant nature of liver foci. Quite commonly they are inaccessible to percutaneous CT-guided puncture, but can be easily reached and biopsied under direct vision or LUS-guidance. By virtue of LUS and its information about extrahepatic lymph node infliction, diagnostic laparoscopy is now a less invasive but equally valid substitute for diagnostic laparotomy prior to liver transplantation in oncological diseases. LUS is now well established in diagnostic laparoscopy as a reliable tool for the preoperative staging of distal esophageal and abdominal tumors. It provides additional information which cannot be obtained with conventional imaging procedures.