Vascular Supply to the Liver: A Report of a Rare Arterial Variant

In the classic description of hepatic arterial supply, the common hepatic artery originates from the coeliac trunk. However, there are numerous variations to this classic pattern. We report a rare variant pattern of hepatic arterial supply and discuss the clinical significance of this variation. 1. Introduction In the classic description of the arterial supply to the liver, the coeliac trunk trifurcates into left gastric, splenic, and common hepatic arteries [1–5]. The common hepatic then bifurcates at its termination into the proper hepatic artery and gastroduodenal arteries [1–5]. However, there are numerous variations to this classic pattern. Michels [6] first described variants of the classic anatomy of the hepatic arteries in 1953. Based on a series of cadaveric dissections, Michels [7] then proposed a classification system that described ten anatomic variants. The classification is in common use to describe variant hepatic arterial branching patterns and allows standardization of anatomic descriptions [8]. We report a variant that is not described by the Michels’ classification [7]. 2. Case Report A 59-year-old female patient with a diagnosis of locally advanced invasive ductal carcinoma of the left breast was referred for a staging CT scan of the abdomen and pelvis. The scan was done using a Philips Brilliance 64 slice multidetector CT scanner. Nonionic contrast media (Ultravist 300) in a volume of 100？mLs were administered via pressure injector at a rate of 3.5？mL/min. The liver was found to be normal; however, she had evidence of metastases to the spleen, several vertebrae, and the pelvis. An incidental finding of abnormal arterial branching was noted at the upper abdominal aorta (Figures 1 and 2). The left gastric artery originated directly from the anterior surface of the abdominal aorta shortly after it entered the abdomen through the diaphragmatic hiatus. Thereafter, it followed its normal course along the lesser curvature of the stomach. At the level of the first lumbar vertebra, there was a large arterial trunk originating from the anterior surface of the aorta, consistent with the celiacomesenteric trunk described by Ishigami et al. [9]. After coursing 2.5？cm, the celiacomesenteric trunk bifurcated into the superior mesenteric artery and the coeliac trunk that was unusually long and tortuous (Figure 3). The splenic artery coursed to the left over the superior mesenteric artery and vein toward the splenic hilum where it divided into segmental arteries to supply the spleen in normal fashion. The left hepatic took an early origin directly