ASSESSMENT OF HEPATIC-ARTERY INVASION BY BILE-DUCT CANCER USING INTRADUCTAL ULTRASONOGRAPHY

Background and Study Aims: This study was performed to clarify the dia gnostic accuracy of intraductal ultrasonography (IDUS) in assessing he patic artery invasion by bile duct cancer. Patients and Methods: Preop erative assessment of hepatic artery invasion was performed by IDUS vi a a percutaneous tract or the transpapillary route in a total of 22 pa tients with extrahepatic bile duct cancer. The probes used had a diame ter of 1.4, 2.0, 2.4, 2.6, and 3.2 mm, and frequencies of 7.5, 15, 20, and 30 MHz. In the first six cases, IDUS images were analyzed retrosp ectively with no knowledge of the operative results or of the other im aging tests. In the following 16 cases, the IDUS images were prospecti vely reviewed prior to surgery without knowledge of the angiographic f indings. The diagnostic accuracy of IDUS was compared with angiography in all cases, with the histopathological results in 20 resected cases , and with the intraoperative findings in two cases with only surgical exploration. Results: IDUS was able to demonstrate the right hepatic artery in all cases, and its accuracy in diagnosing right hepatic inva sion was 100%. However, IDUS was able to visualize the proper hepatic artery in only four cases (18%), and the left hepatic artery in only t hree cases (14%), respectively. IDUS could not visualize the area outs ide of the hepatoduodenal ligament, because of its low penetration dep th. Conclusions: IDUS proved useful for assessing the extension of bil e duct cancer invasion into the right hepatic artery. However, IDUS di d not sufficiently demonstrate the proper hepatic artery and the left hepatic artery for diagnosing vascular involvement.