[Endosonography in diagnosis of distal biliary stenosis].

Diagnostic validity of endoscopic ultrasonography (EUS) was estimated retrospectively in 34 patients, suffering distal biliary stenosis, revealed during endoscopic retrograde cholangiopancreatography or magnet resonance cholangiopancreatography, in whom the cause of the block was not revealed in accordance to the CT data obtained. Nontumoral stenosis was diagnosed, when normal in layers structure of the biliary ducts walls was safe, not depending on a new tumor presence. In other situations stenosis was considered having tumoral genesis. The definite diagnosis of stenosis was established after morphological investigation in 18 patients--postoperatively and during dynamic follow-up--in 16. Diagnostic validity of EUS while determining the stenosis cause have had constituted: sensitivity--94.1%, specificity--82.3%, accuracy--88.2%. In a tumoral stenosis in accordance to the EUS data there was revealed hypoechogenic mass of irregular form, causing the common biliary duct obstruction and the surrounding tissues infiltration. EUS constitutes an effective method of the biliary stenosis estimation, it permits to determine the diagnosis on the early stages.