The use of endoscopic ultrasonography in the detection and differentiation of pathology in the wall of the upper gastrointestinal tract

Introduction
The growing incidence of gastrointestinal diseases forces to improve imaging techniques. Identification of lesions located inside the wall of intestinal tract or in close proximity often was not possible using endoscopy or computed tomography.

Aim
To assess the usefulness of endosonography (EUS) in the differentiation between compression from the outside and intramural lesions of the upper gastrointestinal tract.

Material and methods
For 4 years 20,012 patients with performed gastroscopies were enrolled in the study. One hundred and ninety-nine patients (96 females, 103 males; age 62.2 ±14.1 years) with pathology of the wall of the upper gastrointestinal tract qualified for further diagnosis. Endosonography and computed tomography (CT) were performed in each patient. A chest CT was performed in patients with a lesion in the oesophagus. An abdomen CT was performed in patients with pathology in the stomach or duodenum. Based on the results of EUS, histopathology, and imaging, each patient qualified for treatment, endoscopic observation, surgery, or cancer treatment.

Results
In EUS 129 (64.8%) intramural lesions were identified. Five (2.5%) diagnoses were false negative. In 62 (31.2%) patients no intramural changes were recognised and three (1.5%) results were false positive. The sensitivity and specificity of EUS was 96.3% and 95.4%, respectively, with positive predictive value 90.7%, negative predictive value 97.8%, and overall accuracy 95% (p < 0.05). Endoscopic therapy was performed in 31 (15.6%) patients, and 99 (49.8%) were classified for endoscopic observation. Surgery was performed in 50 (25.1%) patients, and 19 (9.5%) patients required oncologic treatment.

Conclusions
Endosonography exceeds computed tomography in differentiating compression from the outside and intramural lesions of the upper gastrointestinal tract.