Abstract
Background and Study Aims: This study was performed to clarify the diagnostic accuracy of intraductal ultrasonography
(IDUS) in assessing hepatic artery invasion by bile duct cancer.
Patients and Methods: Preoperative assessment of hepatic artery invasion was performed by IDUS via a percutaneous
tract or the transpapillary route in a total of 22 patients with extrahepatic bile
duct cancer. The probes used had a diameter 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
retrospectively with no knowledge of the operative results or of the other imaging
tests. In the following 16 cases, the IDUS images were prospectively reviewed prior
to surgery without knowledge of the angiographic findings. 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 invasion was 100 %. However, IDUS was able to visualize
the proper hepatic artery in only four cases (18 %), and the left hepatic artery in
only three cases (14 %), respectively. IDUS could not visualize the area outside of
the hepatoduodenal ligament, because of its low penetration depth.
Conclusions: IDUS proved useful for assessing the extension of bile duct cancer invasion into
the right hepatic artery. However, IDUS did not sufficiently demonstrate the proper
hepatic artery and the left hepatic artery for diagnosing vascular involvement.
