[Endoscopic ultrasonography and diagnostic algorithms in diseases of the gastrointestinal tract].

This article reviews the recent literature on the role of endoscopic ultrasonography (EUS) as diagnostic and therapeutic tool, defines its place in the algorithm of diagnostic procedures and informs how to treat some patients evaluated by EUS. Endoscopic ultrasonography utilizes the technology of endoscopy to introduce high frequency ultrasound probes in the upper or lower part of gastrointestinal tract to visualize gastrointestinal wall and adjacent structures. This method has come out as an important modality for the diagnosis and staging of benign and malignant lesions of the gut wall and surrounding structures of the mediastinum, abdomen and pelvis. It is also used as a diagnostic tool for the evaluation of submucosal masses of the upper gastrointestinal tract and the rectosigmoid, for locating pancreatic endocrine tumors, and for the assessment of vascular disease. Interventional applications, such as EUS-guided fine-needle aspiration (EUS-FNA) for obtaining tissue/fluid samples, for pseudocyst drainage, and also for delivery of local therapy will likely enhance the clinical utility and cost-effectiveness of this imaging modality. The widest application of EUS is, however, in the diagnosis and staging of esophageal, gastric, rectal, and pancreaticobiliary carcinoma. EUS has been shown to change the approach to clinical management in a significant proportion of patients to a less costly, risky, or invasive strategy.