Mesenteric artery anatomic variants

Imaging description In the classic anatomy, the common hepatic artery (CHA), left gastric artery (LGA) and splenic artery (SA) arise from the celiac axis (CA), and the superior mesenteric artery (SMA) arises from the aorta without an aberrant or accessory hepatic artery (61–76% of normal population) (Figure 84.1). There are multiple types of variant anatomy of these vessels. The most common variations are a replaced or accessory left hepatic artery originating from the LGA (9.7–12.5%), a replaced or accessory right hepatic artery originating from the SMA (7.5–10.6%), or a combination of replaced or accessory right and left hepatic arteries (2.3– 4.5%) (Figure 84.2). Less commonly, the origin of the CHA arises from the SMA (1.5–3%) (Figure 84.3) or directly from the aorta (0.2–2%) (Figures 84.4 and 84.5). In these cases the splenic artery and left gastric artery often arise directly from the aorta (gastrosplenic, or lienogastric trunk) (Figures 84.3 and 84.5). Common origin of the CA and SMA (celiacomesenteric trunk) is seen in 0.7–1.1% of population (Figure 84.6). Other uncommon variations include the splenic artery originating from SMA (splenomesenteric trunk) (0.24% [5]) (Figure 84.7), and the CHA originating from the left gastric artery (hepaticogastric trunk) (0.2– 0.3%) (Figure 84.7). Additional very rare patterns also have been described.Typically, the common hepatic artery has a suprapancreatic, preportal course; however, there can be a variation in the pathway of CHA, such as a retrocaval course or passing through the pancreatic parenchyma, particularly when the CHA arises from the SMA (Figure 84.3).ImportanceFor preoperative planning of the abdominal surgery, it is important to understand the celiac axis, hepatic arterial, and mesenteric arterial anatomy to avoid or minimize serious ischemic complications. To perform interventional radiologic procedures such as intra-arterial hepatic tumor management and embolotherapy for hemorrhage, preprocedural evaluation of variant celiac axis and hepatic arterial anatomy is important for treatment planning.