Assessment of the course and variations of the hepatic artery in bile duct cancer by intraductal ultrasonography

Background: We evaluated the course and variations of the hepatic artery in bile duct cancer using intraductal ultrasonography (IDUS). Methods: IDUS was used to demonstrate the course of the hepatic artery preoperatively in 20 patients with extrahepatic bile duct cancer, and the image was compared with angiographic and surgical findings. Results: IDUS was able to assess tumor invasion to the main branch of the right hepatic artery in all cases. However, it demonstrated only three cases in the left hepatic artery and four cases in the proper hepatic artery. When the hepatic artery indicated re-entry or bifurcation on the IDUS image, the proximal portion of re-entry or bifurcation was established as the proper hepatic artery, but when it showed neither re-entry nor bifurcation it was established as the right hepatic artery. Conclusions: IDUS demonstrated the main branch of the right hepatic artery in all cases, but was not useful for demonstration of the left and proper hepatic arteries. Correct assessment of re-entry and bifurcation was essential on IDUS images for making the distinction between the right hepatic artery and the proper hepatic artery. (Gastrointest Endosc 1996;44:249-56.)