[Percutaneous intraluminal ultrasound studies of the biliary tract in the diagnosis of malignant biliary obstruction].

The diagnostic value of percutaneous intraluminal ultrasound examination of the biliary tract (PIBUS) for the staging of malignancies that had obstructed the biliary tract was assessed in a prospective study. Intrabiliary sonography was performed 25 times in 22 patients (seven women, 15 men; mean age 66.4 +/- 16 years) with obstructive jaundice in whom percutaneous transhepatic drainage of the biliary tract had been undertaken. The obstruction involved the hepatic duct bifurcation in 15 patients, the distal portion of the choledochal duct in five and its central portion as well as hepaticojejunostomy in one patient each. Ultrasound examination made it possible to assess tumour infiltration into the lumen of the biliary tract, its wall or its surrounding structures. Correct T-staging was successful in all 12 patients with carcinoma of the biliary tract (T1: n = 4; T2: n = 2; T3: n = 6), judged against the "gold standard" of exploratory laparotomy in nine. Infiltration of the portal vein was demonstrated in three patients, lymph node metastases in the region of the hepatoduodenal ligament in seven. This experience indicates that PIBUS makes it possible correctly to T-stage carcinoma of the biliary tract, but because of its limited depth penetration it has to be combined with conventional imaging procedures for precise definition of the N and M stages.