Evaluation of Percutaneous Biliary Ultrasonography(PBUS) for the Diagnosis of Cancer of the Papilla of Vater

We performed percutaneous biliary ultrasonography with the thin ultrasonic probe through a percutaneous transhepatic biliary drainage catheter. The normal papilla of Vater consists of five ultrasonographic layers. From the luminal side the high echo (layer 1a) of the first layer corresponds to the mucosa of the common duct. The low echoic area (layer 1b)of the first layer corresponds to the sphincter of Oddi. The second hyperechoic layer corresponds to the submucosa of the duodenum. The third hypoechoic layer and the fourth hyperechoic layer correspond to the mucosa of the duodenum. When the probe was contact with the lumen, the first and second layer was displayed as only a hypoechoic layer. In 10 patients with cancer of the papilla of Vater, accuracy rate of PBUS diagnosis on cancer extension was studied. Accuracy rate on the diagnosis of duodenal invasion was 100%, and that of pancreatic invasion was 90%. PBUS with the thin ultrasonic probe provides an effective imaging for the evaluation of the extension of cancer of the papilla of Vater.