“Supraportal” Right Posterior Hepatic Artery: An Anatomic Trap in Hepatobiliary and Transplant Surgery

Abstract

A supraportal right posterior hepatic artery (RPHA), which runs cranially to the right portal vein and goes to the liver, has never been described. The course of the RPHA to the right portal vein was evaluated, using (1) computed tomography (CT) arteriography and portography in 300 patients who underwent multidetector row CT (radiologic study) and (2) operative records in 203 patients who underwent left-sided hepatectomy for perihilar cholangiocarcinoma (surgical study). In the radiologic study, an infraportal type RPHA was observed in 239 (79.7%) patients, a supraportal type in 35 (11.7%), and a combined type in 26 (8.7%). In the surgical study, an infraportal type was observed in 179 (88.2%) patients, a supraportal type in 11 (5.4%), and a combined type in 13 (6.4%). In two patients with the combined type RPHA, the supraportal hepatic artery of the right posterior superior segment (A7) was injured during surgery. In another two patients with advanced carcinoma involving the supraportal PRHA, combined hepatic artery resection and reconstruction was necessary. Overall, in 4 (17.4%) of the 24 hepatectomized patients with supraportal or combined type RPHA, iatrogenic injury during surgery or cancer invasion of the hepatic artery occurred due to the course of the RPHA itself. In contrast, 179 hepatectomized patients with infraportal type RPHA did not have such course-dependent complications. The supraportal RPHA runs just beneath the right hepatic duct, which may function as an anatomic trap during hepatobiliary and transplant surgery.