Communicating Arcade between the Right and Left Hepatic Arteries: Evaluation with CT and Angiography during Temporary Balloon Occlusion of the Right or Left Hepatic Artery

To evaluate prospectively the relationship between the arterial collateral system at the hepatic hilum and the blood supply to the hilar bile duct by using computed tomography (CT) and angiography during temporary balloon occlusion of the right or left hepatic artery.Institutional review board approval and informed consent were obtained. The study included 13 patients with no lesions at the hepatic hilum (eight men and five women; age range, 41-78 years; mean, 65.8 years). After serial angiographic studies were performed for preoperative evaluation or transcatheter arterial chemoembolization, a 5.5-F catheter with an occlusion balloon was positioned in the right or left hepatic artery. Eleven patients underwent angiography of the left hepatic artery with temporary occlusion of the right hepatic artery, and two patients underwent angiography of the right hepatic artery with temporary occlusion of the left hepatic artery. In addition, 11 patients underwent single-level dynamic CT during hepatic arteriography (CTHA) with temporary occlusion of the right or left hepatic artery. The images from angiography and CTHA were interpreted by two authors who assessed the existence of the arterial communication and its branching points, location, and relationship to the hilar bile duct and caudate lobe.During temporary occlusion of the right or left hepatic artery, the communicating arcade (CA) between the right and left hepatic arteries was immediately evident in all patients. On the left side, the CA originated from the segment IV artery in eight patients (62%) and from the left hepatic artery in five (38%). On the right side, the CA originated from the right anterior hepatic artery in six patients (46%), the right hepatic artery in two (15%), and both arteries in five (38%). The CA was extrahepatically located close to the hilar bile duct and forked into a few branches to the caudate lobe.The CA may play an important role not only in the interlobar arterial collateral system but also in the blood supplies to the caudate lobe and hilar bile duct.