[Percutaneous intraductal ultrasound of the bile ducts]

Miniaturization of ultrasound probes (6 F, 20 MHz) enables to perform intraluminal sonography of the bile duct in patients in whom a percutaneous transhepatic access has been achieved for diagnostic or therapeutic reasons. Initial experiences in 13 patients with malignant bile duct obstruction and in 8 patients with benign bile duct disease are described. Intraluminal ultrasound displays the normal anatomy and pathologic processes of the bile ducts and reveals information on therapeutic procedures within the bile ducts. Malignant tumors and benign strictures can be differentiated in most cases. In malignant disease, this diagnostic method improves the difficult staging of bile duct tumors and gives information on tumor extension, infiltration of adjacent tissues and vessels, and lymph node enlargement. The limited penetration depth of 1.5-2.0 cm creates problems in the staging of tumors particularly at the hepatic hilum. The procedure is simple and devoid of risks, but requires some refinements and improvements to attain a wider use in different clinical problems.