In transcatheter management of hepatic tumors, it is essential to understand hepatic vascular anatomy in detail to enhance therapeutic results and prevent complications due to non-target treatment.
The purpose of this chapter is to review celiac trunk and hepatic artery variations, non-hepatic arteries arising from hepatic arteries, and extrahepatic collateral supply to hepatic tumors.
Celiac trunk anatomy
Normal celiac trunk anatomy and variations
The celiac trunk is a wide branch from the front of the aorta just below the aortic hiatus of the diaphragm. It passes nearly horizontally forward and slightly to the right above the pancreas and the splenic vein, and divides into three major branches of the left gastric artery (LGA), common hepatic artery (CHA), and splenic artery. It may give off one or both inferior phrenic arteries (IPAs), dorsal pancreatic artery, and, rarely, colic or jejunal branches (Figure 12.1). The superior mesenteric artery (SMA) separately arises from the aorta inferior to the origin of the celiac axis. Usually, the LGA is the first major branch of the celiac trunk. However, in about 4% of the population, the LGA directly arises from the supraceliac or juxtaceliac aorta, which represents the most common form of celiac trunk variation. If IPAs arise from the celiac trunk, their origin is almost always located proximal to the LGA (Figure 12.1).
Celiac trunk variation is found in approximately 10% of the general population. Celiac trunk variations can be considered as the result of the origin of the CHA, LGA, splenic artery, and SMA from the aorta in different combinations. Among 15 possible combinations of their origin (Figure 12.2), we could find 13 types in clinical practice.
In describing celiac trunk and hepatic artery variations, it is extremely important to define the terminology used. The CHA should be defined as the common trunk of a hepatic artery (regardless of its size or anatomical distribution) and the gastroduodenal artery (GDA). According to our experience, the most common type of celiac trunk variation was the common trunk of the CHA and splenic artery and the separate origins of the LGA and the SMA from the aorta, which was followed by two separate trunks from the aorta in combination of the CHA and SMA (hepatomesenteric trunk) and that of the LGA and splenic artery (gastrosplenic trunk) (Figure 12.3).